U.S. patent number 5,832,400 [Application Number 08/523,096] was granted by the patent office on 1998-11-03 for controlling vehicular driving force in anticipation of road situation on which vehicle is to run utilizing vehicular navigation system.
This patent grant is currently assigned to Nissan Motor Co.., Ltd.. Invention is credited to Hitoshi Kidokoro, Akira Shiratori, Hiroshi Takahashi.
United States Patent |
5,832,400 |
Takahashi , et al. |
November 3, 1998 |
Controlling vehicular driving force in anticipation of road
situation on which vehicle is to run utilizing vehicular navigation
system
Abstract
In an apparatus and method utilizing a navigation system for
controlling a driving force to be exerted at an estimated position
at which the vehicle is to pass to reach to a destination at which
the vehicle is finally to reach, a running road estimating block
estimates a future position of the own vehicle in which the
vehicular driving force controlling apparatus is mounted on the
basis of a present position of the own vehicle. The estimated
future position is a point of a road for the vehicle to pass
several seconds after a time at which the own vehicle is placed at
the present position specified from a recorded content of an
electronic road map stored in, for example, CD-ROM. A driving force
predicting block determines a present vehicular load state derived
by a running resistance measuring block as a required driving force
at the estimated position by correcting the present vehicular load
state by a height difference between the estimated position and the
present position. A driving system controlling block changes a
setting of an engine and/or automatic power transmission according
to a magnitude of the required driving force at the present
position.
Inventors: |
Takahashi; Hiroshi (Tokyo,
JP), Kidokoro; Hitoshi (Yokohama, JP),
Shiratori; Akira (Yokohama, JP) |
Assignee: |
Nissan Motor Co.., Ltd.
(Kanagawa, JP)
|
Family
ID: |
16992431 |
Appl.
No.: |
08/523,096 |
Filed: |
September 1, 1995 |
Foreign Application Priority Data
|
|
|
|
|
Sep 5, 1994 [JP] |
|
|
6-235867 |
|
Current U.S.
Class: |
701/53; 701/58;
701/65 |
Current CPC
Class: |
B60W
30/18 (20130101); G01C 21/26 (20130101); B60W
10/10 (20130101); B60W 10/04 (20130101); B60K
31/00 (20130101); B60W 30/1819 (20130101); B60W
2555/40 (20200201); F16H 2059/666 (20130101); F02D
2200/063 (20130101); F16H 2061/0015 (20130101); B60W
2520/10 (20130101); B60W 2530/00 (20130101); B60W
2510/0657 (20130101); B60W 2552/15 (20200201); F16H
2059/142 (20130101); F16H 2300/14 (20130101); F16H
2059/663 (20130101); B60W 2530/16 (20130101); B60W
2556/50 (20200201) |
Current International
Class: |
G01C
21/26 (20060101); B60K 31/00 (20060101); G08G
1/0968 (20060101); F16H 59/14 (20060101); F16H
61/00 (20060101); B60K 031/04 () |
Field of
Search: |
;364/424.082,424.083,424.084,424.085,424.087,424.094,431.04,431.051,431.054
;701/53,54,55,56,58,65,102,103,106 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2-48210 |
|
Feb 1990 |
|
JP |
|
2-194406 |
|
Aug 1990 |
|
JP |
|
2-231611 |
|
Sep 1990 |
|
JP |
|
2-310800 |
|
Dec 1990 |
|
JP |
|
3-182841 |
|
Aug 1991 |
|
JP |
|
4-218435 |
|
Aug 1992 |
|
JP |
|
Primary Examiner: Cuchlinski, Jr.; William A.
Assistant Examiner: Pipala; Edward
Attorney, Agent or Firm: McDermott, Will & Emery
Claims
What is claimed is:
1. A control apparatus for an automotive vehicle, comprising:
a) electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads;
b) vehicle present position determining means for determining a
present position of the vehicle;
c) running road estimating means for referring to the stored road
map information using present position of the vehicle so as to
receive said road map information for the vehicle, and for
estimating a future position of the vehicle, said estimated future
position of the vehicle being a future position of the vehicle
several seconds after a time at which the vehicle has been placed
at the determined present position;
d) running resistance measuring means for deriving a present
vehicle load condition imposed on a vehicular driving system at the
determined present position of the vehicle;
e) driving force predicting means for correcting the present
vehicular load condition at the determined present position of the
vehicle so as to predict a required driving force at the future
estimated position of the vehicle as a function of the gradient
information between the determined present position of the vehicle
and the estimated future position of the vehicle; and
f) vehicular driving system controlling means for adjusting in
advance a setting of a driving characteristic of at least one of a
vehicular engine and an engine associated automatic power
transmission installed in the vehicle driving system as a function
of the predicted driving force at the estimated future position of
the vehicle so as to suppress a fuel consumption as low as possible
within a range such that the fuel consumption enables the vehicular
driving system to exert the required driving force at the estimated
future position of the vehicle.
2. A control apparatus for an automotive vehicle as claimed in
claim 1, wherein said driving force predicting means further
comprises:
driving force margin calculating means for estimating a required
driving force margin at the estimated future position of the
vehicle as a function of at least one of an input operating
variable of the vehicular driving system and an output operating
variable of the vehicular driving system, and
wherein said vehicular driving system controlling means adjusts the
setting of the driving characteristic of at least one of the
automotive engine and the engine associated automatic power
transmission in advance so as to correspond to the required driving
force including the required driving force margin.
3. A control apparatus for an automotive vehicle as claimed in
claim 1, wherein said driving system controlling means comprises
vehicular driving system total controlling means for selecting any
one of a plurality of combinations which corresponds to the
required driving force, the combinations including a combination
between an air-fuel mixture ratio of the engine and a gear range
shifting characteristic of the automatic power transmission, and
for adjusting a modification timing of the settings of the
combinations so as to secure a continuity in a driveability of the
vehicular driving system, thus, performing a total control over the
vehicular driving system.
4. A control apparatus for an automotive vehicle, comprising:
a) electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads;
b) vehicle present position specifying means for specifying a
present position of the vehicle;
c) running road estimating means for referring to the stored road
map information as a function of the specified present position of
the vehicle so as to derive a present position of the vehicle with
respect to the road map information, and for estimating a future
position of the vehicle as a function of the derived present
position of the vehicle, said estimated future position of the
vehicle being a future position of the vehicle several seconds
after the vehicle has been placed at the specified present
position;
d) vehicular running resistance measuring means for deriving a
present vehicle load condition imposed on a vehicular driving
system at the specified present position of the vehicle;
e) driving force predicting means for correcting the present
vehicular load condition at the specified present position of the
vehicle so as to predict a required driving force at the estimated
future position of the vehicle as a function of the gradient
information between the specified present position of the vehicle
and the estimated future position of the vehicle searched from the
electronic road map storing means;
f) driving system controlling means for adjusting in advance a
setting of a driving characteristic of at least one of a vehicular
engine and an engine associated automatic power transmission
installed in the vehicle driving system as a function of the
predicted driving force at the estimated future position of the
vehicle so as to suppress a fuel consumption as low as possible
within a range such that the fuel consumption enables the vehicular
driving system to exert the required driving force at the estimated
position of the vehicle; and
g) target point inputting means for inputting and setting a target
position of the vehicle on a route of travel to which the vehicle
is to reach through said target point inputting means by an
operator in connection with the road map information, and
wherein said running road estimating means comprises moving means
for moving the estimated future position of the vehicle along a
road branched from a branching point and having a relatively high
directional tendency toward the set target position of the route of
travel in a case where the estimated future position of the vehicle
is placed so as to jump over the branching point with respect to
the present position of the vehicle.
5. A control apparatus for an automotive vehicle as claimed in
claim 4, wherein said driving system controlling means comprises
vehicular driving system total controlling means for selecting any
one of a plurality of combinations which corresponds to the
required driving force, the combinations including a combination
between an air-fuel mixture ratio of the engine and a gear range
shifting characteristic of the automatic power transmission, and
for adjusting a modification timing of the settings of the
combinations so as to secure a continuity in a driveability of the
vehicular driving system, thus, performing a total control over the
vehicular driving system.
6. A control apparatus for an automotive vehicle comprising:
a) electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads;
b) vehicle present position determining means for determining a
present position of the vehicle;
c) running road estimating means for referring to the stored road
map information using the determined present position of the
vehicle so as to receive said road map information, and for
estimating a future position of the vehicle as a function of the
determined present position of the vehicle, said estimated future
position of the vehicle being a future position of the vehicle
several seconds after a time at which the vehicle has been placed
at the present position;
d) running resistance measuring means for deriving a present
vehicle load condition imposed on a vehicular driving system at the
determined present position of the vehicle;
e) driving force predicting means for correcting the present
vehicular load condition at the determined present position of the
vehicle so as to predict a required driving force at the estimated
future position of the vehicle as a function of the gradient
information between the determined present position of the vehicle
and the estimated future position of the vehicle from the
electronic road map storing means; and
f) driving system controlling means for adjusting in advance a
setting of a driving characteristic of at least one of a vehicular
engine and an engine associated automatic power transmission
installed in the vehicle driving system as a function of the
predicted driving force at the estimated future position of the
vehicle so as to suppress a fuel consumption as low as possible
within a range such that the fuel consumption enables the vehicular
driving system to exert the required driving force at the estimated
future position of the vehicle, and wherein said running road
estimating means further comprises forward direction identifying
means for detecting an operation intent of the vehicular driver
corresponding to a forward direction of the vehicle and identifying
the forward direction of the vehicle at a road branching point and
estimated future position moving means for moving the estimated
future position along a branched road corresponding to the forward
direction of the vehicle identified by said forward direction
identifying means when the estimated future position of the vehicle
is placed so as to jump over the road branching point.
7. A control apparatus for an automotive vehicle as claimed in
claim 6, wherein said driving system controlling means comprises
vehicular driving system total controlling means for selecting any
one of a plurality of combinations which corresponds to the
required driving force, the combinations including a combination
between an air-fuel mixture ratio of the engine and a gear range
shifting characteristic of the automatic power transmission, and
for adjusting a modification timing of the settings of the
combinations so as to secure a continuity in a driveability of the
vehicular driving system, thus, performing a total control over the
vehicular driving system.
8. A control apparatus for an automotive vehicle comprising:
a) electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads, said electronic road map storing
means being arranged so as to be rewritable therein on a new
information at each point on a running route of travel of the
vehicle in relation to the road map information;
b) vehicle present position determining means for determining a
present position of the vehicle;
c) running road estimating means for referring to the stored road
map information using the determined present position of the
vehicle so as to receive said road map information, and for
estimating a future position of the vehicle as a function of the
determined present position of the vehicle, said estimated future
position of the vehicle being the future position of the vehicle
several seconds after a time at which the vehicle has been placed
at the determined present position;
d) running resistance measuring means for deriving a present
vehicle load condition imposed on a vehicular driving system at the
determined present position of the vehicle;
e) driving force predicting means for correcting the present
vehicular load condition at the determined present position of the
vehicle so as to predict a required driving force at the estimated
future position of the vehicle as a function of the gradient
information between the determined present position of the vehicle
and the estimated future position of the vehicle;
f) driving system controlling means for adjusting in advance a
setting of a driving characteristic of at least one of a vehicular
engine and an engine associated automatic power transmission
installed in the vehicle driving system in advance in time as a
function of the predicted driving force at the estimated future
position of the vehicle so as to suppress a fuel consumption as low
as possible within a range such that the fuel consumption enables
the vehicular driving system to exert the required driving force at
the estimated future position of the vehicle; and
g) running locus recording means for detecting an ever-changing
information related to the driving force generated by the vehicle
during a run of the vehicle and for storing and recording the
detected ever-changing information on said rewritable electronic
road map storing means, and
wherein said driving system controlling means comprises correcting
means for correcting in advance a content of adjustment according
to the required driving force as a function of the past
ever-changing information related to the driving force generated by
the vehicle at the estimated future position of the vehicle.
9. A control apparatus for an automotive vehicle as claimed in
claim 8, wherein said driving system controlling means comprises
vehicular driving system total controlling means for selecting any
one of a plurality of combinations which corresponds to the
required driving force, the combinations including a combination
between an air-fuel mixture ratio of the engine and a gear range
shifting characteristic of the automatic power transmission, and
for adjusting a modification timing of the settings of the
combinations so as to secure a continuity in a driveability of the
vehicular driving system, thus, performing a total control over the
vehicular driving system.
10. A control apparatus for an automotive vehicle as claimed in
claim 8, wherein the ever-changing information related to the
driving force generated by the vehicle includes the ever-changing
information related to a vehicle speed exerted by the vehicle.
11. A control apparatus for an automotive vehicle comprising:
a) electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads, said electronic road map storing
means being arranged so as to be rewritable therein on a new
information at each point on a running route of travel of the
vehicle in relation to the road map information;
b) vehicle present position predicting means for determining a
present position of the vehicle;
c) running road estimating means for referring to the stored road
map information using the determined present position of the
vehicle so as to receive said road map information, and for
estimating a future position of the vehicle as an estimated
position of the vehicle as a function of the determined present
position of the vehicle, said estimated future position of the
vehicle being a future position of the vehicle several seconds
after a time at which the vehicle has been placed at the determined
present position;
d) running resistance measuring means for deriving a present
vehicle load condition imposed on a vehicular driving system at the
determined present position of the vehicle;
e) driving force predicting means for correcting the present
vehicular load condition at the determined present position of the
vehicle so as to predict a required driving force at the estimated
future position of the vehicle as a function of the gradient
information between the determined present position of the vehicle
and the estimated future position of the vehicle;
f) driving system controlling means for adjusting in advance a
setting of a driving characteristic of at least one of a vehicular
engine and an engine associated automatic power transmission
installed in the vehicle driving system as a function of the
predicted driving force at the estimated future position of the
vehicle so as to suppress a fuel consumption as low as possible
within a range such that the fuel consumption enables the vehicular
driving system to exert the required driving force at the estimated
future position of the vehicle;
g) generated driving force deriving means for deriving an
ever-changing driving force output state of the vehicle during a
run of the vehicle; and
h) evaluating means for evaluating a numerical value related to a
gap between the required driving force at the estimated future
position of the vehicle and an actual driving force output state at
the estimated future position of the vehicle and storing and
recording the derived numerical value on said rewritable electronic
road map storing means, and
wherein said driving system controlling means comprises correcting
means for correcting a content of an adjustment in anticipation
according to the past numerical value related to said gap searched
from said rewritable electronic road map storing means.
12. A control apparatus for an automotive vehicle as claimed in
claim 11, wherein said driving system controlling means comprises
vehicular driving system total controlling means for selecting any
one of a plurality of combinations which corresponds to the
required driving force, the combinations including a combination
between an air-fuel mixture ratio of the engine and a gear range
shifting characteristic of the automatic power transmission, and
for adjusting a modification timing of the settings of the
combinations so as to secure a continuity in a driveability of the
vehicular driving system, thus, performing a total control over the
vehicular driving system.
13. A control apparatus for an automotive vehicle comprising:
a) electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads;
b) vehicle present position determining means for determining a
present position of the vehicle;
c) running road estimating means for referring to the stored road
map information using the determined present position of the
vehicle so as to receive said road map information, and for
estimating a future position of the vehicle as an estimated future
position of the vehicle as a function of the determined present
position of the vehicle, said estimated future position of the
vehicle being a future present position of the vehicle several
seconds after a time at which the vehicle has been placed at the
determined present position;
d) running resistance measuring means for deriving a present
vehicle load condition imposed on a vehicular driving system at the
determined present position of the vehicle;
e) driving force predicting means for correcting the present
vehicular load condition at the determined present position of the
vehicle so as to predict a required driving force at the estimated
future position of the vehicle as a function of the gradient
information between the determined present position of the vehicle
and the estimated future position of the vehicle;
f) driving system controlling means for adjusting in advance a
setting of a driving characteristic of at least one of a vehicular
engine and an engine associated automatic power transmission
installed in the vehicle driving system as a function of the
derived driving force at the estimated future position of the
vehicle so as to suppress a fuel consumption as low as possible
within a range such that the fuel consumption enables the vehicular
driving system to exert the required driving force at the estimated
future position of the vehicle; and
g) vehicular driver operation intention detecting means for
detecting an ever-changing operating variable of an engine throttle
valve of the vehicle by a vehicular driver during the run of the
vehicle so as to determine a variation of a driving pattern of the
vehicular driver, and
wherein said driving system controlling means comprises correcting
means for correcting a content of the adjustment in advance of the
setting so as to relieve the suppression of the fuel consumption
when a variation width in the operating variable of the engine
throttle valve detected by the vehicular driver operation intention
detecting means is expanded.
14. A control apparatus for an automotive vehicle as claimed in
claim 13, wherein said driving system controlling means comprises
vehicular driving system total controlling means for selecting any
one of a plurality of combinations which corresponds to the
required driving force, the combinations including a combination
between an air-fuel mixture ratio of the engine and a gear range
shifting characteristic of the automatic power transmission, and
for adjusting a modification timing of the settings of the
combinations so as to secure a continuity in a driveability of the
vehicular driving system, thus, performing a total control over the
vehicular driving system.
15. A method for controlling a driving force exerted by an
automotive vehicle, comprising the steps of:
a) storing a road map information, said road map information
including at least a gradient information of roads;
b) determining a present position of the vehicle using a GPS
receiving system;
c) referring to the stored road map information as a function of a
result of determination of the present position of the vehicle at
the step b) so as to derive a present position of the vehicle with
respect to the road map information, and estimating a future
position of the vehicle as a function of the derived present
position of the vehicle, said estimated future position of the
vehicle being a future position of the vehicle several seconds
after a time at which the vehicle has been placed at the determined
present position;
d) deriving a present vehicle load condition imposed on a vehicular
driving system at the determined present position of the
vehicle;
e) correcting the present vehicular load condition at the
determined present position of the vehicle so as to derive a
required driving force at the estimated future position of the
vehicle as a function of the gradient information between the
present position of the vehicle and the estimated future position
of the vehicle searched from step a); and
f) adjusting in advance a setting of a driving characteristic of at
least one of a vehicular engine and an engine associated automatic
power transmission installed in a vehicle driving system as a
function of the derived driving force at the estimated future
position of the vehicle so as to suppress a fuel consumption as low
as possible within a range such that the fuel consumption enables
the vehicular driving system to exert the required driving force at
the estimated future position of the vehicle.
16. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 15, wherein said several
seconds are about two seconds and longer.
17. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 16, wherein said step e)
further comprises the step g), of monitoring at least one of an
operation input state and an output state of the vehicular driving
system and estimating a driving force margin required at said
estimated future position as a function of a result of the
monitoring, and
wherein at said step f), the setting of the driving force
characteristic of at least one of the vehicular engine and the
engine associated automatic power transmission is adjusted in
advance as a function of said driving force and said estimated
driving force margin required at the estimated future position.
18. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 16, which further comprises
the step g) responding to vehicular occupant's setting of a route
of travel and of a target position to which the vehicle is to be
reached along the set route of travel in connection with road map
information displayed on a screen of a display unit and wherein
said step c) further comprises the steps of h) determining whether
the estimated position is placed at a position jumped over a road
branching point and i) moving said estimated position along a road
branched from said road branching point which has a relatively high
directional tendency toward the target position along the set route
of travel.
19. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 16, wherein said step c)
further comprises the steps of: g) monitoring a vehicular driver's
operation intent corresponding to a forward direction toward which
the vehicle is to be forwarded so as to identify the forward
direction at a road branching point and h) moving said estimated
future position along a road branched from the road branching point
corresponding to the forward direction of the vehicle when the
estimated future position of the vehicle is jumped over the road
branching point.
20. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 16, which further comprises
the step of g) monitoring an ever-changing information related to
the driving force generated during a vehicular run and recording
and storing the monitored ever-changing information on a rewritable
electronic road map which is so arranged and constructed as to
enable rewriting of a new information at each point of a route of
travel along which the vehicle is to run and wherein said step f)
further comprises the step of h) correcting a content of the
adjustment at said step f) in accordance with the required driving
force as a function of a past ever-changing information related to
the driving force the vehicle generated during the vehicular run
searched from said rewritable electronic road map.
21. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 20, wherein the
ever-changing information related to the driving force the vehicle
generated includes a vehicle velocity.
22. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 16, which further comprises
the steps of: g) monitoring an ever-changing driving force output
state of the vehicle during the run of the vehicle; h) deriving a
numerical value related to a gap between the estimated required
driving force to be exerted at the estimated future position and an
actually monitored driving force exerted at the estimated future
position so as to evaluate the required driving force and i)
recording and storing the numerical value related to the gap onto a
rewritable electronic road map which is so arranged and constructed
as to enable writing of a new information at each point of a route
of travel along which the vehicle is to run and wherein said step
f) further comprises the step of: i) correcting a content of
adjustment at said step f) in accordance with the required driving
force as a function of a past numerical value related to the gap
stored and recorded on the rewritable electronic road map.
23. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 16, which further comprises
the steps of: g) monitoring an ever-changing opening angle of an
engine throttle valve operated by a vehicle driver of the vehicle
through an accelerator of the vehicle so as to detect a variation
in a vehicle driver's driving pattern; h) determining whether a
variation width of the monitored ever-changing opening angle is
expanded so as to exceed a threshold value of the variation width;
and i) correcting a content of the adjustment of the setting
carried out at said step f) so as to relieve the suppression of the
fuel consumption when determining that the variation width is
expanded at said step g).
24. A method for controlling a driving force exerted by an
automotive vehicle as claimed in claim 15, wherein, at said step
f), a total control of the driving system of a vehicle is carried
out such that any one of a plurality of combinations which
corresponds to the required driving force, the combinations
including a combination between an air/fuel mixture ratio of an
engine of the vehicular driving system and a gear range shifting
characteristic of an engine associated automatic power
transmission, and a modification timing of the settings of the
combinations is adjusted in advance in time so as to secure a
continuity in a driveability of the vehicular driving system.
25. A control apparatus for an automotive vehicle, comprising:
a) an electronic road map storage unit for storing a road map
information, the road map information including at least a gradient
information of roads;
b) vehicle present position determinator for determining a present
position of the vehicle;
c) a running road estimator for referring to the stored road map
information using the determined present position of the vehicle
and for estimating a future position of the vehicle as an estimated
future position of the vehicle as a function of the determined
present position of the vehicle, a estimated future position of the
vehicle being a future position of the vehicle several seconds
after a time at which the vehicle is placed at the determined
present position of the vehicle;
d) a running resistance measuring instrument for deriving a vehicle
load condition imposed on a vehicular driving system at the
determined present position of the vehicle;
e) a driving force predictor for correcting the present vehicular
load condition at the determined present position of the vehicle so
as to predict a required driving force at the estimated future
position of the vehicle as a function of the gradient information
between the determined present position of the vehicle and the
estimated position of the vehicle estimated from the electronic
road map storage unit; and
f) a vehicular driving system controller for adjusting in advance a
setting of a driving characteristic of at least one of a vehicular
engine and an engine associated with an automatic power
transmission installed in the vehicle driving system as a function
of the predicted driving force at the estimated future position of
the vehicle so as to suppress a fuel consumption as low as possible
within a range such that the fuel consumption enables the vehicular
driving system to exert the required driving force at the estimated
future position of the vehicle.
26. A control apparatus for a driving system of an automotive
vehicle, the driving system including at least one of a vehicular
engine and an engine associated automatic power transmission
installed in the vehicle, the control apparatus comprising:
a road map memory for storing a road map information, the road map
information including gradient information of roads;
a position sensor for detecting a present position of the
vehicle;
a determination circuit for determining the present position of the
vehicle on the map information according to the position detected
by the position sensor;
a running resistance measuring circuit for measuring a running
distance imposed on the vehicle at the detected position;
a future position estimating circuit for estimating a future
position of the vehicle on the road map information, which
represents the position of the vehicle a few seconds in the future,
according to the determined present position and a running
condition of the vehicle at the determined present position;
a driving force calculating circuit for calculating the driving
force required at the estimated future position according to the
running resistance at the determined present position and the
gradient information between the determined present position and
the estimated future position stored in the road map memory;
and
a driving controller for controlling a driving characteristic of
the driving system including at least one of a vehicular engine and
an engine associated automatic power transmission so that the
characteristic is optimum when the vehicle runs at the future
position.
Description
BACKGROUND OF THE INVENTION
The present invention relates to apparatus and method for
controlling a vehicular driving force in anticipation of a road
situation on which the vehicle is to run utilizing a vehicular
navigating system. The present invention, more particularly,
relates to apparatus and method for controlling the vehicular
driving force which adjusts operation modes of a power train, such
as at least either or both of automotive engine or automatic power
transmission basically with a gradient of a road to be passed
several seconds after a time at which the vehicle is at the present
position and to be searched from an electronic road map taken into
consideration.
A vehicular navigation system has been put into practice in which a
route guidance from the present position of the vehicle (vehicle
start position) to a destination to which the vehicle is finally to
reach is carried out with a past running locus of the own vehicle
(in which the navigation system is mounted) and the present
position of the vehicle superimposed on a road map as an image
displayed on a TV monitor screen. U.S. Pat. No. 5,371,678 issued on
Dec. 6, 1994 exemplifies such a vehicular navigating apparatus as
described above.
Such a vehicular navigating apparatus as described above includes:
a) a play-back unit for a CD-ROM storing a commercially available
electronic road map on the same region of which a large quantity of
associated road map information is recorded; b) a plurality of
sensors and a receiver for a satellite information to detect the
present position of the vehicle; c) a calculation (arithmetic and
logic operation) unit used to calculate the own vehicle position,
to search the electronic road map, to extract the corresponding
road map information, and to perform an image processing on the
basis of the extracted road map information; and d) a monitor
screen on which the present position of the own vehicle is
superimposed on the displayed road map. If the vehicular navigating
apparatus is provided with a rewritable recording medium such as a
magnetic disc (disk) (floppy disk) or IC memory as the electronic
road map in addition to the available (already set) CD-ROM, the
navigating apparatus records the information searched from the
CD-ROM which is combined with the new information on the added
recording medium so as to enable a user to prepare a special
purpose minor data base. An example of the special-purpose minor
data base includes a technique in which with a running route set by
a vehicular driver stored, the set running route is superimposed on
the road map displayed on the monitor screen and includes another
technique in which the vehicular driver sets a start point at which
the vehicle is to start and a destination at which the vehicle is
finally to reach and a shortest route from the start point to the
destination is automatically searched.
Next, suppose such a running situation that the vehicle once
ascends a short slope, thereafter, descends a continued short
slope, and again ascends a further continued long slope.
In order to save a fuel consumption, suppress a vehicular
compartment noise and vehicular vibration, purify an exhaust gas of
the vehicle, and reduce vehicular contaminations, various
techniques which automatically adjust operating conditions of
either or both of the automotive engine and associated automatic
power transmission during the vehicular running have been put into
practice.
For example, when a vehicular sensing apparatus detects a
high-speed steady-state running (so called, cruise speed run)
during the vehicle run on a freeway, the automotive engine is
controlled in a high air-fuel mixture ratio mode, namely, in a lean
burn control mode and/or a gear range shifting characteristic of
the associated automatic power transmission is changed to a higher
gear range shifting characteristic mode or lower gear range
shifting characteristic mode from a normal gear range shifting mode
in order to accommodate to an output condition of the engine.
In these techniques, an optimum operating condition is set to
either or both of the engine and associated automatic power
transmission which corresponds to an ever-changing present
vehicular load situation. When the vehicle starts to ascend the
first short slope with the automotive engine in the lean burn
control mode, an insufficiency in the engine output is
automatically detected so that the lean burn control mode of the
air-fuel mixture ratio control is automatically switched to a,
so-called, stoichiometric control mode in which the air-fuel
mixture ratio control is controlled to make the present air/fuel
mixture ratio approach to a stoichiometric air/fuel mixture
ratio.
In such a technique that the optimum operating condition of either
or both of the engine and automatic power transmission
corresponding to the present vehicular load condition is set to
either or both of the engine and associated automatic power
transmission, a time duration during which the control mode
switching is carried out causes a substantial reduction in an
automotive driving performance. For example, about two seconds are
required from a time at which a signal is input to a fuel supply
system of the engine to a time at which the engine output state is
actually changed to respond to the control mode change in a case
where the switching between the two air-fuel mixture ratio control
modes is carried out. In addition, about one second is required
from a time at which a gear shift ratio characteristic switching is
commanded to the automatic power transmission to a time at which
the actual gear shifting is completed to respond to the gear range
shifting characteristic. It is noted that in the vehicular run at
100 Km/h, two seconds correspond to the run through 60 m and one
second run corresponds to 30 meter run. Therefore, when the vehicle
enters an ascending slope having a length shorter than 100 m and
the engine air-fuel mixture ratio control mode is switched after
the reduction of the engine output is detected, the ascending slope
is about to be ended or already ended at a time when the engine
output is actually increased. During the run on the ascending
slope, the vehicle driver feels that the vehicular speed is
gradually reduced even if an accelerator pedal associated with an
engine throttle valve is strongly depressed to accelerate the
vehicle and feels that the power train of the vehicle itself has an
insufficient power and a worsened response of the power train to
the depression of the accelerator pedal is resulted even though
these situations are caused by the operating condition of the
engine to achieve the lower fuel consumption. Hence, if a necessary
switching operation is completed before the vehicle enters the
ascending slope, the operating condition of the engine to achieve
the lower fuel consumption is halted, and the operating conditions
such that the engine gives a high power output and gives a highly
response characteristic are set, such unfavorable feelings of the
vehicle driver as described above can be avoided.
In the technique such that the settings of the operating conditions
for the engine and/or automatic power transmission are switched
according to the present vehicular load condition, unnecessary
switching operations occur in addition to the problem of the
substantial control mode switching time duration described
above.
As described before, in the case where the vehicle runs on such an
ascending slope as described above in which the long ascending
slopes are continued with the short descending short slope segment
placed between the long ascending slopes. In this case, it has no
advantage that the engine air-fuel mixture ratio control mode is
switched to the lean burn control mode during the vehicular run on
such a short descending slope segment as described above. It is
rather than better to avoid carrying out the setting change
unnecessary for the engine and/or automatic power transmission, in
anticipation of a presence in a change in a road gradient at a
forward direction of the vehicle. That is to say, if there is no
advantage in switching the settings of the engine and/or automatic
power transmission, a high engine output power and a highly
responsive characteristic should be assured even if the vehicle
receives a minor disadvantage in consuming fuel during the
vehicular run on a midway (,i.e., the short descending slope)
through the ascending slope. In addition, it is doubtful whether
the vehicle can achieve the fuel economy during the run on the
short descending slope before the long continued ascending slope,
with the length of the substantial time duration during which the
control mode switching is carried out taken into consideration.
A Japanese Patent Application First Publication No. Heisei 2-48210
published on Feb. 19, 1990 exemplifies a previously proposed
vehicular characteristic switching apparatus in which a vehicular
body behavior characteristic is predictively switched so as to
accommodate to a forward state far away from the road on which the
vehicle is running, utilizing the vehicular navigating
apparatus.
In the above-identified Japanese Patent Application First,
Publication, while the vehicle driver is driving the vehicle along
the set route of travel with the route of travel set before the
start of the drive, the CD-ROM road map information is predictively
searched on the basis of the present position of the own vehicle
specified by the navigating apparatus and an optimum suspension
(damping force) characteristic and/or a steering characteristic of
the vehicle according to such a road attribute as a slope, freeway,
or rough (ragged) road before the vehicle enters such a slope,
freeway, or rough road is automatically set.
Hence, if such a technique as the predictive switching method of
the vehicular (body) characteristic as disclosed in the
above-identified Japanese Patent Application First Publication is
expanded, such a technique that the operating condition of either
or both of the engine and associated automatic power transmission
is predictively (anticipative) switched would be conceivable. That
is to say, at a timely varying running position during the
vehicular run, the CD-ROM is predictively searched along the
driver'set running route and the optimum engine air-fuel mixture
ratio characteristic and automatic power transmission gear shifting
characteristic, both of which accord with the road attributes such
as the slope, freeway, and rugged road, are automatically set
before an actual entrance of the vehicle into such the slope,
freeway, and rugged road as described above. Then, if the technique
of the predictive control for the power train system of the vehicle
according to an anticipation of the route of the travel along which
the vehicle is to run is combined with the technique of the route
search from the CD-ROM, the operating conditions of either or both
of the engine and associated automatic power transmission can
predictively be switched without setting of the running route of
travel before the start of the vehicle disclosed in the
above-identified Japanese Patent Application First Publication.
In details, during the vehicular run along the set route of travel,
a future position of the own vehicle several seconds later than the
present position of the vehicle is estimated at a running position
varied with time, a road attribute information at the running
position several seconds after the time at which the vehicle is at
the present position (such as a gradient, attitude, width, radius
of curvature, distinction between paved road or unpaved road, and
so forth) is read from the CD-ROM, and the optimum engine air-fuel
mixture ratio and gear range shifting characteristic of the
automatic power transmission are set according to these road
attributes.
However, in this case, it is necessary to give numerical values of
tremendous amounts of initial conditions such as a vehicular load
weight, a number of vehicular occupants, a kind of fuel used in the
engine, surrounding temperature and moisture, wear levels of road
wheels, personality of the vehicle driver, and so forth to the
engine and/or automatic power transmission as initial conditions.
The optimum settings of the engine and/or associated automatic
power transmission are largely different according to these initial
conditions. Then, if the setting of these initial conditions are
rested on the driver's operation, an appropriate management of the
initial conditions cannot be expected due to the troublesome in
setting the initial conditions. In addition, if various sensors are
installed to detect the initial conditions in place of the
vehicular driver's settings, the system of setting the operating
conditions of the engine and/or automatic power transmission
requires a great number of sensors, accessory circuits, and signal
processing devices. Consequently, such a system as described above
becomes expensive and has a low practicability.
SUMMARY OF THE INVENTION
It is, therefore, a main object of the present invention to provide
an apparatus and method for controlling a vehicular driving force
utilizing a vehicular navigating system having a high
practicability in which a future vehicular running position several
seconds after a time at which the present position is estimated to
search road attributes at the estimated running position so that
the settings of driving characteristics in an automotive engine
and/or associated automatic power transmission are optimally and
precisely adjusted.
The above-described object can be achieved by providing a control
apparatus for an automotive vehicle, comprising: a) electronic road
map storing means for storing a road map information, said road map
information including at least a gradient information of roads; b)
vehicle present position specifying means for specifying a present
position of the vehicle; c) running road estimating means for
referring to the stored road map information on the basis of a
result of specification of the present position of the vehicle by
said vehicle present position specifying means so as to derive a
present position of the vehicle on the road map information, and
for estimating a future position of the vehicle as an estimated
position of the vehicle on the basis of the derived present
position of the vehicle, said estimated position of the vehicle
being the future present position of the vehicle several seconds
after a time at which the vehicle is placed at the present
position; d) running resistance measuring means for deriving a
vehicle load condition imposed on a vehicular driving system at the
specified present position of the vehicle; e) driving force
predicting means for correcting the present vehicular load
condition at the present position of the vehicle so as to derive a
required driving force at the estimated position of the vehicle on
the basis of the gradient information between the present position
of the vehicle and the estimated position of the vehicle searched
from the electronic road map storing means; and f) vehicular
driving system controlling means for adjusting a setting of a
driving characteristic of at least one of a vehicular engine or
engine associated automatic power transmission installed in the
vehicle driving system in advance in time on the basis of the
derived driving force at the estimated position of the vehicle so
as to suppress a fuel consumption as low as possible within a range
such that the fuel consumption enables the vehicular driving system
to exert the required driving force at the estimated position of
the vehicle.
The above-described object can also be achieved by providing a
control apparatus for an automotive vehicle, comprising: a)
electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads; b) vehicle present position
specifying means for specifying a present position of the vehicle;
c) running road estimating means for referring to the stored road
map information on the basis of a result of specification of the
present position of the vehicle by said vehicle present position
specifying means so as to derive a present position of the vehicle
on the road map information, and for estimating a future position
of the vehicle as an estimated position of the vehicle on the basis
of the derived present position of the vehicle, said estimated
position of the vehicle being the future present position of the
vehicle several seconds after the vehicle is placed at the present
position; d) vehicular running resistance measuring means for
deriving a vehicle load condition imposed on a vehicular driving
system at the specified present position of the vehicle; e) driving
force predicting means for correcting the present vehicular load
condition at the present position of the vehicle so as to derive a
required driving force at the estimated position of the vehicle on
the basis of the gradient information between the present position
of the vehicle and the estimated position of the vehicle searched
from the electronic road map storing means; f) driving system
controlling means for adjusting a setting of a driving
characteristic of at least one of a vehicular engine or engine
associated automatic power transmission installed in the vehicle
driving system in advance in time on the basis of the derived
driving force at the estimated position of the vehicle so as to
suppress a fuel consumption as low as possible within a range such
that the fuel consumption enables the vehicular driving system to
exert the required driving force at the estimated position of the
vehicle; and g) target point inputting means for inputting and
setting a target position of the vehicle on a route of travel to
which the vehicle is to reach through said target point inputting
means by an operator in connection with the road map information,
and wherein said running road estimating means comprises moving
means for moving the estimated position of the vehicle along a road
branched from a branching point and having a relatively high
directional tendency toward the set target position of the route of
travel in a case where the estimated position of the vehicle is
placed so as to jump over the branching point with respect to the
present position of the vehicle.
The above-described object can also be achieved by providing a
control apparatus for an automotive vehicle comprising: a)
electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads; b) vehicle present position
specifying means for specifying a present position of the vehicle;
c) running road estimating means for referring to the stored road
map information on the basis of a result of specification of the
present position of the vehicle by said vehicle present position
specifying means so as to derive a present position of the vehicle
on the road map information, and for estimating a future position
of the vehicle as an estimated position of the vehicle on the basis
of the derived present position of the vehicle, said estimated
position of the vehicle being the future present position of the
vehicle several seconds after a time at which the vehicle is placed
at the present position; d) running resistance measuring means for
deriving a vehicle load condition imposed on a vehicular driving
system at, the specified present position of the vehicle; e)
driving force predicting means for correcting the present vehicular
load condition at the present position of the vehicle so as to
derive a required driving force at the estimated position of the
vehicle on the basis of the gradient information between the
present position of the vehicle and the estimated position of the
vehicle searched from the electronic road map storing means; and f)
driving system controlling means for adjusting a setting of a
driving characteristic of at least one of a vehicular engine or
engine associated automatic power transmission installed in the
vehicle driving system in advance on the basis of the derived
driving force at the estimated position of the vehicle so as to
suppress a fuel consumption as low as possible within a range such
that the fuel consumption enables the vehicular driving system to
exert the required driving force at the estimated position of the
vehicle, and wherein said running road estimating means further
comprises forward direction identifying means for detecting an
operation content of the vehicular driver corresponding to a
forward direction of the vehicle and identifying the forward
direction of the vehicle at a road branching point and estimated
position moving means for moving the estimated position along a
branched road corresponding to the forward direction of the vehicle
identified by said forward direction identifying means when the
estimated position of the vehicle is placed so as to jump over the
road branching point.
The above-described object can also be achieved by providing a
control apparatus for an automotive vehicle comprising: a)
electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads, said electronic road map storing
means being arranged so as to be rewritable therein on a new
information at each point on a running route of travel of the
vehicle in relation to the road map information; b) vehicle present
position specifying means for specifying a present position of the
vehicle; c) running road estimating means for referring to the
stored road map information on the basis of a result of
specification of the present position of the vehicle by said
vehicle present position specifying means so as to derive a present
position of the vehicle on the road map information, and for
estimating a future position of the vehicle as an estimated
position of the vehicle on the basis of the derived present
position of the vehicle, said estimated position of the vehicle
being the future present position of the vehicle several seconds
after a time at which the vehicle is placed at the present
position; d) running resistance measuring means for deriving a
vehicle load condition imposed on a vehicular driving system at the
specified present position of the vehicle; e) driving force
predicting means for correcting the present vehicular load
condition at the present position of the vehicle so as to derive a
required driving force at the estimated position of the vehicle on
the basis of the gradient information between the present position
of the vehicle and the estimated position of the vehicle searched
from the electronic road map storing means; f) driving system
controlling means for adjusting a setting of a driving
characteristic of at least one of a vehicular engine or engine
associated automatic power transmission installed in the vehicle
driving system in advance in time on the basis of the derived
driving force at the estimated position of the vehicle so as to
suppress a fuel consumption as low as possible within a range such
that the fuel consumption enables the vehicular driving system to
exert the required driving force at the estimated position of the
vehicle; and g) running locus recording means for detecting an
ever-changing information related to the driving force generated by
the vehicle during the run of the vehicle and for storing and
recording the detected ever-changing information related to the
driving force generated by the vehicle on said rewritable
electronic road map storing means, and wherein said driving system
controlling means comprises correcting means for correcting a
content of adjustment in anticipation according to the required
driving force on the basis of the past ever-changing information
related to the driving force generated by the vehicle at the
estimated position of the vehicle searched from the rewritable
electronic road map storing means.
The above-described object can also be achieved by providing a
control apparatus for an automotive vehicle comprising: a)
electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads, said electronic road map storing
means being arranged so as to be rewritable therein on a new
information at each point on a running route of travel of the
vehicle in relation to the road map information; b) vehicle present
position specifying means for specifying a present position of the
vehicle; c) running road estimating means for referring to the
stored road map information on the basis of a result of
specification of the present position of the vehicle by said
vehicle present position specifying means so as to derive a present
position of the vehicle on the road map information, and for
estimating a future position of the vehicle as an estimated
position of the vehicle on the basis of the derived present
position of the vehicle, said estimated position of the vehicle
being the future present position of the vehicle several seconds
after a time at which the vehicle is placed at the present
position; d) running resistance measuring means for deriving a
vehicle load condition imposed on a vehicular driving system at the
specified present position of the vehicle; e) driving force
predicting means for correcting the present vehicular load
condition at the present position of the vehicle so as to derive a
required driving force at the estimated position of the vehicle on
the basis of the gradient information between the present position
of the vehicle and the estimated position of the vehicle searched
from the electronic road map storing means; f) driving system
controlling means for adjusting a setting of a driving
characteristic of at least one of a vehicular engine or engine
associated automatic power transmission installed in the vehicle
driving system in advance in time on the basis of the derived
driving force at the estimated position of the vehicle so as to
suppress a fuel consumption as low as possible within a range such
that the fuel consumption enables the vehicular driving system to
exert the required driving force at the estimated position of the
vehicle; g) generated driving force deriving means for deriving an
ever-changing driving force output state of the vehicle during the
run of She vehicle; and h) evaluating means for deriving a
numerical value related to a gap between the required driving force
at the estimated position of the vehicle and an actual driving
force output state at the estimated position of the vehicle derived
by the generated driving force deriving means and storing and
recording the derived numerical value on said rewritable electronic
road map storing means, and wherein said driving system controlling
means comprises correcting means for correcting a content of an
adjustment in anticipation according to the past numerical value
related to said gap searched from said rewritable electronic road
map storing means.
The above-described object can also be achieved by providing a
control apparatus for an automotive vehicle comprising: a)
electronic road map storing means for storing a road map
information, said road map information including at least a
gradient information of roads; b) vehicle present position
specifying means for specifying a present position of the vehicle;
c) running road estimating means for referring to the stored road
map information on the basis of a result of specification of the
present position of the vehicle by said vehicle present position
specifying means so as to derive a present position of the vehicle
on the road map information, and for estimating a future position
of the vehicle as an estimated position of the vehicle on the basis
of the derived present position of the vehicle, said estimated
position of the vehicle being the future present position of the
vehicle several seconds after a time at which the vehicle is placed
at the present position; d) running resistance measuring means for
deriving a vehicle load condition imposed on a vehicular driving
system at the specified present position of the vehicle; e) driving
force predicting means for correcting the present vehicular load
condition at the present position of the vehicle so as to derive a
required driving force at the estimated position of the vehicle on
the basis of the gradient information between the present position
of the vehicle and the estimated position of the vehicle searched
from the electronic road map storing means; f) driving system
controlling means for adjusting a setting of a driving
characteristic of at least one of a vehicular engine or engine
associated automatic power transmission installed in the vehicle
driving system in advance on the basis of the derived driving force
at the estimated position of the vehicle so as to suppress a fuel
consumption as low as possible within a range such that the fuel
consumption enables the vehicular driving system to exert the
required driving force at the estimated position of the vehicle;
and g) vehicular driver operation intention detecting means for
detecting an ever-changing operating variable of an engine throttle
valve of the vehicle by a vehicular driver during the run of the
vehicle so as to determine a variation of a driving pattern of the
vehicular driver, and wherein said driving system controlling means
comprises correcting means for correcting a content of the
adjustment in advance of the setting so as to relieve the
suppression of the fuel consumption when a variation width in the
operating variable of the engine throttle valve detected by the
vehicular driver operation intention detecting means is
expanded.
The above-described object can also be achieved by providing a
method for controlling a driving force exerted by an automotive
vehicle, comprising the steps of: a) storing a road map
information, said road map information including at least a
gradient information of roads; b) specifying a present position of
the vehicle using a GPS receiving system; c) referring to the
stored road map information on the basis of a result of
specification of the present position of the vehicle at the step b)
so as to derive a present position of the vehicle on the road map
information, and estimating a future position of the vehicle as an
estimated position of the vehicle or the basis of the derived
present position of the vehicle, said estimated position of the
vehicle being the future present position of the vehicle several
seconds after a time at which the vehicle is placed at the present
position; d) deriving a vehicle load condition imposed on a
vehicular driving system at the specified present position of the
vehicle; e) correcting the present vehicular load condition at the
present position of the vehicle so as to derive a required driving
force at the estimated position of the vehicle on the basis of the
gradient information between the present position of the vehicle
and the estimated position of the vehicle searched from the step
a); and f) adjusting a setting of a driving characteristic of at
least one of a vehicular engine or engine associated automatic
power transmission installed in a vehicle driving system in advance
on the basis of the derived driving force at the estimated position
of the vehicle so as to suppress a fuel consumption as low as
possible within a range such that the fuel consumption enables the
vehicular driving system to exert the required driving force at the
estimated position of the vehicle.
In the vehicular driving force controlling apparatus according to
the present invention, the electronic road map, the own vehicle
position specifying means, and running road estimating means
constitute a navigating system. The electronic road map includes at
least gradient information for each point of place on the road
segments as an attribute information on the road map information.
The gradient information includes a height (land height)
information by which the gradient of the running road segment can
indirectly be identified. The position detecting means is
constituted by a combination of a gyro sensor (gyroscope) and a
running distance sensor or GPS (Global Positioning System)
satellite broadcasting receiver. The running road estimating means
executes an estimation operation for the future vehicular position
several second after the present position on the basis of the
derived present position of the vehicle in addition to the
specification operation of the present vehicular position in the
same way as the well known navigating system executes. The driving
force predicting means executes a relative correction for the
driving force according to a gradient difference between the
present position and the estimated position on the basis of actual
driving system load condition and driving force output condition of
the vehicle itself at the present position of the vehicle.
Therefore, it is not necessary to search for the equal variables
between the present position and the estimated position such as the
quantity of cargo mounted on the vehicle (vehicle load weight), the
number of vehicular occupants, road wheel condition, running road
surface condition, and so forth so that an accurate estimation of a
required driving force becomes possible even if the above-described
variables are unknown. The driving system controlling means
optimizes an engine air-fuel mixture ratio and/or gear range
shifting characteristic of the automatic power transmission
according to the load condition at the estimated position (which is
replacable with an average value or a maximum value of the load
condition at an interval of distance from the present position to
the estimated position) which is relatively derived by the driving
force predicting means from the anticipated information. The
optimization means the achievement of improvement in the fuel
economy, purification of exhaust gas, and so forth avoiding
unnecessary switching operations in a range for the vehicular
driver not to feel the insufficiency of driving power and the
worsening in acceleration command responsive characteristic. It is
noted that the estimated position means a point of place through
which the vehicle is to pass several seconds after the vehicle has
run through the present position. It is also noted that the several
seconds after the vehicle has run through the present position
means a time duration equal to or more than a delay time (time lag)
from a time at which the signal to indicate the setting change for
the engine and/or automatic power transmission of the vehicle is
input to a time at which the result of setting change is actually
reflected on the output of the driving system (driving power train)
of the vehicle. Hence, the interval of distance between the present
position and the estimated position may be varied according to the
instantaneous vehicle running speed. The required driving force at
the estimated position may be corrected according to such an
information as a kind of road (freeway or national roadway), radius
of curvature, and so forth searched from the electronic road map in
addition to the gradient difference between the present position
and estimated position. The running road estimating means, the
running resistance measuring means, the driving force predicting
means, driving system controlling means correspond to the
processing of data calculations, comparison, and determination so
that it is possible for theses means to correspond to a part of
program to be executed by one or more arithmetic operation units
including a memory unit in the practical manner.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of a vehicular driving force
controlling apparatus in a first preferred embodiment according to
the present invention.
FIG. 2 is a circuit block diagram of a vehicular driving force
controlling apparatus in the first preferred embodiment according
to the present invention.
FIG. 3A is an explanatory view for explaining a road situation of a
vehicular run on a slope in the case of the vehicular driving force
controlling apparatus in the first embodiment.
FIG. 3B is an explanatory view for explaining control contents of
the vehicular driving force controlling apparatus in the first
embodiment.
FIG. 4 is a processing flowchart of determination in anticipation
of distance to an estimated road point executed in a running road
estimating block of the vehicular driving force controlling
apparatus in the first embodiment.
FIGS. 5 and 6 are integrally a driving force controlling flowchart
executed in the first embodiment shown in FIGS. 1 and 2.
FIG. 7 is an explanatory view for explaining the switchings
between, a lower gear range shifting, a normal gear range shifting,
and a higher gear range shifting characteristics.
FIG. 8A is a functional block diagram of the vehicular driving
apparatus in a second preferred embodiment according to the present
invention.
FIG. 8B is a characteristic graph representing a relationship
between added quantity of a driving force margin and standard
deviation for the accelerator pedal operation.
FIG. 9 is an operational flowchart of a driving force margin in a
modification of the second embodiment shown in FIG. 8A.
FIG. 10 is a functional block diagram of vehicular a driving force
controlling apparatus in a third preferred embodiment according to
the present invention.
FIG. 11A is a functional block diagram of a vehicular driving force
controlling apparatus in a fourth preferred embodiment according to
the present invention.
FIG. 11B is an explanatory view for explaining a technique for
estimating a future position of a road to be passed which is jumped
over an intersection.
FIG. 12A is a functional block diagram of the vehicle driving force
controlling apparatus in a fifth preferred embodiment according to
the present invention.
FIG. 12B is an explanatory view for explaining a position of an
estimated (future) road point which is jumped over an intersection
G in the case of the fifth embodiment.
FIG. 13A is a functional block diagram for explaining a vehicular
driving apparatus in a sixth preferred embodiment according to the
present invention.
FIG. 13B is an explanatory view for explaining a memory area in a
rewritable electronic road map in the sixth preferred
embodiment.
FIG. 14 is an explanatory view for explaining an example of a
running state of the own vehicle in which the vehicular driving
force controlling apparatus is mounted.
FIGS. 15A is a functional block diagram for explaining the
vehicular driving force controlling apparatus in a seventh
preferred embodiment according to the present invention.
FIG. 15B is an example of a processing flowchart to be executed in
an evaluation block 32 in the seventh preferred embodiment.
FIG. 16 is a functional block diagram of the vehicular driving
force controlling apparatus in an eighth preferred embodiment
according to the present invention.
FIGS. 17A and 17B are characteristic graphs representing an
accelerator pattern change due to a psychological (mental) state on
the basis of which the vehicular driving force controlling
apparatus carries out in the eighth embodiment.
FIG. 18A is an explanatory view for a situation of the vehicle to
run on an estimated position of the vehicle which is jumped over an
intersection with respect to the present position of the
vehicle.
FIG. 18B is an explanatory view for a situation of the vehicle run
to approach to a, for example, tollgate on a freeway.
BEST MODE FOR CARRYING OUT THE INVENTION
Reference will hereinafter be made to the drawings in order to
facilitate a better understanding of the present invention.
(First Embodiment)
FIG. 1 and FIG. 2 show integrally a schematic functional block
diagram of a vehicular driving force controlling apparatus in a
first preferred embodiment according to the present invention.
FIGS. 3A and 3B show explanatory views for explaining a prediction
processing of the vehicular driving force executed in the first
embodiment.
FIG. 4 shows an explanatory flowchart for explaining a
determination of an anticipation of distance executed in the first
embodiment.
FIGS. 5 and 6 integrally show an operational flowchart for a
driving force control processing executed in the first
embodiment.
FIG. 7 shows an explanatory view for explaining a gear range
shifting characteristic change in a normal fluid coupling (gear
range shifting type) variable automatic power transmission to which
the present invention is applicable.
It is noted that FIG. 3A shows a relationship between a gradient of
a road and a driving force exerted by the vehicle and FIG. 3B shows
the content of control executed in the first embodiment.
In the first embodiment, the present driving force exerted by the
vehicle is corrected according to a gradient difference between an
estimated position defined as a passage point through which the
vehicle is to pass several seconds after the time at which the
vehicle is at the present position of the vehicle.
As described above, FIG. 1 shows the functional block diagram of
the vehicular driving force controlling apparatus utilizing a
vehicular navigating system in the first embodiment and FIG. 2
shows the individual circuit block diagram version of the first
embodiment of the vehicular driving force controlling apparatus
shown in FIG. 1.
In FIG. 1, an own vehicle position specifying block 11 (the won
vehicle means a vehicle in which the driving force controlling
apparatus according to the present invention is mounted and in
operation) outputs a signal indicating the specification of the
position of the own vehicle in a format not related to a road map,
the specified position indicating a position coordinate of a
latitude and a longitude on the Earth, a direction and distance of
the present position from a specific point of location. An
electronic road map 12 stores a data formatted road map and various
types of information searchable for each location of roads
including at least a road gradient (height) information
therefrom.
A running road estimating block 13 searches the electronic road map
12 using the own vehicle position derived from the own vehicle
position specifying block 11 for a running road on the road map
stored in the electronic road map 12 and for the present position
of the own vehicle on the running road. In addition, the running
road estimating block 13 derives an estimated position of the own
vehicle several seconds after the present position of the own
vehicle which is several ten meters through one hundred meters
ahead of the present position in the vehicular forwarding
direction. The running road estimating block 13 retrieves various
information related to an interval from the present position to
this future position from the electronic road map 12 and holds the
various information so as to be enabled to be transmitted to a
running resistance measuring block 14 and a driving force
predicting block 15.
The running resistance measuring block 14 calculates the present
running resistance of the own vehicle from an output signal of a
torque sensor S1 (as will be described later), referring to the
information read from the running road estimating block 13.
The driving force predicting block 15 corrects a value of the
present running resistance of the own vehicle derived by the
running resistance measuring block 14 on the basis of the input
information from the running road estimating block 14 so as to
estimate a required driving force at the estimated position (or the
interval of distance from the present position to the estimated
position) placed several ten meters or one hundred meter ahead. The
driving force control block 16 sets operating variables of a
vehicular engine and/or automatic power transmission in a vehicular
driving system on the basis of a level of the required driving
force estimated on the basis of the previously read information. It
is noted that a block denoted in a broken line and denoted by A1
carries out an arithmetic operation processing section.
On the other hand, in FIG. 2, a block denoted in the broken line
and denoted by A2 is constituted by a, so-called, a navigating
apparatus.
A GPS receiver 21 specifies the latitude and longitude that the
vehicle occupies on the Earth by receiving GPS satellite electric
waves transmitted from satellites. The GPS receiver 21 is
exemplified by U.S. Pat. Nos. 4,899,285 issued on Feb. 6, 1990 and
4,743,913, the disclosures of which are herein incorporated by
reference.
A CD-ROM play-back unit (or CD-ROM driver) 22 searches a CD-ROM
(Compact Disc Read Only Memory) inserted into the CD-ROM play-back
unit on the basis of an input search signal and outputs a searched
information from the CD-ROM. The CD-ROM is recorded with image data
on the road map having a plurality of stages of scale reduction
percentages with a constant regional area, road data related to
roads on the map on which the vehicle can run, and accessory
information related to each point of the roads.
The accessory information includes gradients or heights of the
roads with respect to, for example, sea level. A image display unit
24 outputs a navigation image synthesized with a CAD (Computer
Aided Design) image prepared by an arithmetic operation unit
(including a microprocessor) 23 itself and road map image
transferred from the CD-ROM for the vehicular driver. An operation
block 25 includes a keyboard, finger touch sensors virtually imaged
on an image screen of the image display unit 24, and various kinds
of switches. The operation block 25 can be used to set a navigating
destination (a target location) to which the vehicle is finally to
reach in advance of a driving start of the vehicle
therethrough.
The arithmetic operation unit 23 converts the input signals
thereinto, calculates a predetermined series of operations, and
communicates with peripheral devices in accordance with
predetermined processing programs and performs a total control over
the peripheral devices and various sensors S so as to achieve a
predetermined system function. It is noted that the arithmetic
operation unit 23 includes a signal processing circuitry which
numerically converts the input signals using A/D
(Analog-to-Digital) converters and counters. As far as the normal
navigation function is concerned, the arithmetic operation unit 23
searches the CD-ROM play-back unit 22 using the own vehicle
position date specified by the GPS (Global Positioning System)
receiver 21 so as to read out the road data and accessory
information together with the required road map image. The
arithmetic operation unit 23 forms the CAD image representing a
running locus (a trajectory along which the vehicle has run) and
the position of the own vehicle on the basis of such data or
information as described above.
It is noted that the electronic road map 12 shown in FIG. 1
includes a combination of both CD-ROM play-back unit 22 and a
memory unit 29.
It is also noted that the own vehicle position specifying block 11
corresponds to the GPS receiver 21. The GPS receiver 21 is
exemplified by U.S. Pat. Nos. 4,899,285 issued on Feb. 6, 1990 and
4,743,913 issued on May 10, 1988, the disclosures of which is
herein incorporated by reference.
A part A1 enclosed by the broken line of FIG. 1 corresponds to a
driving force control program in terms of the software which is an
interrupt program in a navigation processing routine as will be
described later.
A controller 26 outputs command signals to change the present
settings of driving characteristics of both a vehicular engine
(internal combustion engine) 27 and its associated torque converter
equipped automatic power transmission 28 on the basis of contents
of control signals, i.e., an engine control signal and an automatic
power transmission control signal derived from the driving system
(power train) controlling block 16.
In FIG. 2, various sensors S include the torque sensor S1 shown in
FIG. 1 whose output signal is used in the driving force control
program. The memory unit 29 includes a magnetic disc
recording/play-back unit and an IC memory unit. The memory unit 29
an ever-changing information searched by the running road
estimating block 13 from the CD-ROM in relation to the road data.
In addition, the memory unit 29 integrally records the road data
related to a set route of travel and accessory information into its
memory area, both of which are searched from the CD-ROM play-back
unit 22. The memory unit 29 can also additionally record data
derived from the various sensors S and other arithmetic data during
the vehicular run as accessory information thereinto.
Next, in FIG. 3A, in the first embodiment, at the present position
P of the own vehicle at which the driving force f(P) is actually
exerted, the driving force f(x) at the forward position x at which
the vehicle is to pass several seconds after the present position P
is estimated. The setting changes according to the estimated
driving force f(x) are carried out for the engine 27 and automatic
power transmission 28.
The running road estimating block 13 determines a present running
direction from a past running locus (trajectory) derived by the
navigating system and estimates a position x to which the
determined running direction is extended about 100 meter ahead of
the present position P along the route of travel. The driving force
predicting block 15 corrects the actually exerted driving force
f(P) at the position P using a gradient difference h between the
gradients of the present position P and the estimated position x so
as to estimate q required driving force f(x) at the estimated
position x. The driving system controlling block 16 sets the engine
27 and automatic power transmission 28 via the controller 26 so as
to suppress a fuel consumption in a rage capable of securing the
required driving force f(x). The height h(P) at the position P and
a height difference h(x) between the position x and the present
position P are derived from the heights searched from the road data
on the position P and position x from the electronic road map 12.
It is noted that the electronic road map 12 also records the height
h(n) at a position n placed before the present position P by a
distance .alpha..
As shown in FIG. 3B, the driving force f(P) at the present position
P can directly be measured using the torque sensor S1 disposed on
an output axle of the automatic power transmission 28. The
structure of the torque sensor S1 is exemplified by a U.S. Pat. No.
5,419,207 issued on May 30, 1995, the disclosure of which is herein
incorporated by reference.
A torque on an engine output axle may be derived by referring to an
engine driving characteristic map 27A according to an opening angle
of an engine throttle valve detected by an acceleration opening
angle sensor S2 and an engine revolution speed and a transmission
torque may be derived by referring to a torque converter
characteristic map 28A according to an input revolution speed of
the torque converter and an output revolution speed thereof of the
torque converter of the automatic power transmission 28. The
accelerator opening angle sensor S2 detects an revolved angle of an
engine throttle valve and is different from an accelerator sensor
S7 as will be described later.
Anyway, suppose that the driving force f(P) has been exerted at an
interval of distance from the position n to the position P, the
driving force f(x) at the position x several seconds later can be
derived using the following technique.
The running resistance of the vehicle is a sum of a rolling
resistance Rr, an aerial resistance Ra, and an acceleration
resistance Rc. In the first embodiment, the required driving force
f(x) several seconds after the present position P is derived by a
correction of the present position driving force f(P) by a value
corresponding to a gap (differential) of the ascending slope Re
supposing that the summed running resistances listed below except
the ascending slope resistance Re do not vary at the present
position position P and and even at the estimated position x. In
details, since the rolling resistance Rr is a resistance related to
a total weight of the vehicle, the rolling resistance does not vary
from that at the position P even to that at the estimated position
x. Even if instantaneous increase and decrease in the operating
variable of the throttle valve are present, the same acceleration
is deemed to be executed if the acceleration variation for a long
period of time is averaged. Hence, the acceleration resistance Rc
does not vary from the present position P and position x.
Especially, the acceleration resistance Rc does not vary from that
at the position P and that at the position x. Especially, if the
speed is constant, the acceleration resistance Rc is zero.
If an inclination angle of the ascending slope is .alpha., the
ascending slope resistance Re to lift the own vehicle is a value of
the total weight W multiplied by sin.alpha.. During the run of the
vehicle on the slop having the inclination angle of .alpha.,
suppose that the height by the height h with respect to the sea
level is varied for a horizontal distance of 1. When the angle
.alpha. is small, sin.alpha. can be approximate to h/1. Hence, the
ascending slope resistance Re is expressed as: Re=Wh/1.
The running resistance R(P) at the present position of the vehicle
P becomes coincident with the driving force f(P) supposing that the
vehicle runs at the cruise sped (the vehicle speed is constant) so
that the acceleration resistance Rc gives zero.
Similarly, the running resistance R(x) at the estimated position x
several seconds after the present position becomes coincident with
the required driving force f(x).
Since Rr(P)=Rr(x)=constant and Ra(P)=Ra(x)=constant, the required
driving force f(x) is derived from the equations (1) and (2).
Suppose that [Re(x)-Re(P)]=k.multidot.H(x).
It is noted that k denotes a constant representing the driving
force required to lift the total weight W of the vehicle by a unit
of height and is derived from the driving force obtained according
to an engine driving force map (map with respect to the engine
revolution speed and accelerator opening angle). It is also noted
that H(x) denotes a height difference from the position P to the
position x. Consequently, the equation (3) gives
f(x)=f(P)+k.multidot.H(x) so that the required driving force can
simply be derived from the measurable output value f(P) at the
present position P and the height difference H(x) derived according
to the searched information through the CD-ROM play-back unit
32.
The required driving force f(x) is different depending upon how far
is the estimated position x away from the present position P, i.e.,
the distance between the present position and the estimated
position. The reason that a control target f(x) of the driving
force is set in an anticipation read of the electronic road map 12
is that it takes a time to operate the switching of the settings of
the engine driving characteristic and automatic power transmission
and it is not in time to perform the switchings at a time when the
future situation has be noticed. For example, in a case where the
switching from a lean control mode to a stoichiometric control mode
as a lean burn condition is carried out, it takes about two
seconds. In a case where to perform the switching of the gear range
shifting characteristic of the torque converter equipped stepwise
gear range shifting automatic power transmission about one second
is required. Hence, if the required setting changes are started
with the driving force f(x) at the estimated position x about two
second ahead of the present position P, the anticipation control is
achieved so that the vehicular driver is not aware of a delay in
control. In a case where the vehicle runs at a speed of 100 km/h,
the estimated position x is 30 through 60 meters ahead of the
present position since the vehicle runs about 30 seconds per
second. In the anticipation control anticipating a temporary halt
at an intersection or at a signal, it is convenient to be enabled
to anticipate 100 meter through 200 meter ahead. If the temporary
halt at the forward direction is assured, the engine can be in the
lean control mode and the automatic power transmission gear range
shift can be inhibited since the vehicle can be predicted to move
in an inertial run.
It is necessary to vary the estimated position depending on a
running environment or driving pattern. For example, in a case
where a variation in the running speed is hard (violent), the
distance (time) in the anticipation of the estimated position is
shortened and in a case where the variation in the running speed is
minor, the distance (time) in the anticipation of the estimated
position is elongated. In addition, when the vehicle approaches the
intersection and which of a branched direction from the
intersection the vehicle is to be forwarded is not determined, an
anticipation control after the intersection is temporarily halted
until the vehicle is to pass through the intersection.
FIG. 4 shows a flowchart for explaining the anticipation control
processing when the vehicle is to pass through the traffic
intersection as described above.
As shown in FIG. 4, the program determines whether the vehicle is
running at a step 101. If No at the step 101, the routine goes to a
step 102 in which the program specifies the road on which the
vehicle is running and the forward direction. At a step 103, the
program determines the position ahead of the present position along
the road.
At a step 104, the position x which has exceeded or jumped over the
intersection from the present position P is not estimated until the
present position P can be defined as a road of one of the branched
roads on the intersection with the present position P passed
through the intersection.
However, basically, as the distance (time) in anticipation requires
longer, is becomes easier for the control to utilize the longer
distance (time). Here, the driving force f(x) are estimated for
estimated positions of x per 10 meters over a range 100 meter ahead
of the present position P and an average value or maximum value of
ten driving forces f(x) provides a target driving force at an
interval of distance of 100 meters.
It is noted that the driving force f(x) and f(P) are treated as
instantaneous values, respectively.
However, if the values of f(x) and f(P) are varied for the
respective sampling periods, the control targets are
instantaneously switched and a driveability of the vehicle may, in
turn, be worsened. From these respects, the driving force f(x) or
f(P) may be replaced with the driving force F(X) and F(P) derived
using a moving average. For example, a moving average F(P)
(n=arbitrary natural number) is defined as:
F(P)=((n-1).times.F(P-.delta.)+f(P))/n so that an instantaneous
variation component is eliminated. In this way, if the required
driving force f(x) or its moving average F(x) at the interval of
distance up to the point x or its moving average F(X) is derived,
the driving system controlling block 16 determines how the engine
and automatic power transmission are controlled in order to achieve
the driving force f(x).
The driving system controlling block 16 controls the air/fuel
mixture ratio of the engine 27, the gear range shifting
characteristic of the automatic power transmission 28, and a
lock-up of the torque converter in accordance with the flowcharts
of FIGS. 5 and 6 via the controller 26 shown in FIG. 2.
The controller 26 controls the air/fuel mixture ratio of the engine
27 and either of a lean control having a large air/fuel mixture
ratio or a stoichiometric control defined to be in a stoichiometric
air/fuel mixture ratio is selectable.
FIG. 7 shows a gear range shifting characteristic in the associated
automatic power transmission having the torque converter and a
lock-up control. As shown in FIG. 7, the switching timings are
shown in which a first speed range G1, a second speed range G2, a
fourth speed range G4 are provided in its order with respect to the
vehicle velocity. It is noted that a timing at which the gear shift
is transferred from the third gear shifting range G3 to the fourth
gear shifting range G4 is selectable from three modes, namely, a
high-geared characteristic, a normal characteristic, and a
low-geared characteristic. The high-geared characteristic is such
that a gear of a lower gear shift ratio is switched before the
opening angle of the accelerator (throttle valve) becomes large and
an automatic gear shift is executed having a higher priority of the
suppression of the engine revolution speed than the engine output
power. On the other hand, the lower geared characteristic is such
that a higher gear shift ratio is used until the engine revolution
speed is considerably high and, thus, a horse power (engine output
power can be taken out. The normal characteristic gives an
intermediate characteristic of both higher geared and lower geared
characteristics.
In addition, when the torque converter is locked up, a torque
transmission efficiency is enhanced but a torque amplification
action of the a torque converter during a high load is lost. If the
lock-up is released, the torque amplification action is functioned,
thus the power during the high load condition is increased. It is
noted that a signal indicating the release of the lock-up or
indicating the engagement of the lock-up is commanded in addition
to a setting signal of the switching of the gear shift range
characteristics (lower-geared, normal, or higher-geared) is
transmitted from the controller 26 to the automatic power
transmission 28. It is noted that the engine 27 and automatic power
transmission 28 have at least one control unit to receive the
signals from the controller 26.
The series of processing executed by the driving system controlling
block 16 will be described with reference to FIGS. 5 and 6.
In the flowchart shown in FIGS. 5 and 6, the driving force derived
as the moving average calculation is used. However, the moving
averaged driving force can be replaced with a simply averaged value
of the instantaneous driving forces, the maximum value of the
instantaneous driving forces, and the driving force at one
anticipated point of road.
First, at a step 111, the driving system controlling block 16
(constituted by a CPU and hereinafter called CPU) determines the
present control mode of either the lean control mode or the
stoichiometric control, the present gear range shifting
characteristic of any one of the lower-geared characteristic, the
normal characteristic, or the higher-geared characteristic, and
whether the torque converter is in the locked-up (engaged)
state.
At steps of 112 and 113, the CPU calculates the moving average
value of the presently generated driving force (hereinbelow, called
a generated driving force T) and calculates a moving average of an
estimated driving force (hereinbelow, called estimated driving
force X) at the interval of distance ahead of the present position
from the generated driving force T and a plurality of road gradient
data with the present position P and the plurality of gradient data
searched on the basis of the plurality of estimated positions x
within the forward interval of distance from the CD-ROM (electronic
road map 12).
Up to these steps of 112 and 113, the estimated driving force X
does not include the driving force margin according to the kinds of
roads and according to the different vehicular driver.
At a step S114, the routine goes to a step 117 in the case where
the engine 37 is in the lean control (Yes). In the case where the
engine 37 is in the stoichiometric control mode (No), the routine
goes to a step 115.
If the CPU determines that the estimated driving force X is smaller
than the generated driving force T by a constant width during the
stoichiometric air/fuel mixture ratio control at the step 115, the
routine goes to a step 116 immediately in which the engine control
mode is switched to the lean air/fuel mixture ratio control mode
since it is not necessary to provide the present output power for
the engine 27. If the estimated driving force X is larger than the
generated driving force T by the predetermined width at the step
117, the routine goes to a step 118 in which the control mode of
the air/fuel mixture of the engine 27 is immediately switched to
the normal stoichiometric air/fuel mixture control mode since the
present output power of the engine 27 is insufficient. In another
case, namely, in the case where the estimated driving force X falls
in a range generally equal to the generated driving force T (No at
the step 117 and No at the step 115), the routine goes to a step
119 since no inconvenience would occur with the air/fuel mixture
ratio control mode left unchanged. It is noted that X>T at the
step 117 means that X is sufficiently large than T+.delta. and
X<T at the step 115 is sufficiently smaller than T-.delta.. A
symbol .delta. denotes a threshold for the comparison between X and
T and is derived empirically according to an experimental data.
Then, the routine goes to the steps 119 and 122 to change the
settings of the gear range shifting characteristics of the
automatic power transmission 28 according to the result of
comparison of the driving forces of X and T. If the present setting
of the gear range shifting characteristic at the step 119 is in the
higher geared characteristic (Yes at the step 119) and X>T at a
step 120 (Yes), it means that the driving power is insufficient so
that the routine goes to a step 121 to change the setting of the
higher geared characteristic to the normal characteristic. If the
present gear shifting characteristic is not in the higher geared
characteristic (No) at the step 119, the routine goes to a step 122
in which the CPU determines whether the present setting of the gear
range shifting characteristic is in the normal characteristic. If
Yes at the step 122, the routine goes to a step 123 in which the
CPu determines whether X<T. If No at the step S123 (X>T), the
routine goes to a step 127 in which the present normal
characteristic is changed to the lower-geared shifting
characteristic since even at the normal characteristic the output
power of the driving train is insufficient. On the other hand, if
No at the step 119 and No at the step 122, it means that the
present setting of the gear range shifting characteristic is in the
lowered gear shifting characteristic and the routine goes to a step
124. At the step 124, the CPU determines whether X<T. If the
present gear range shifting characteristic is in the lower geared
characteristic (No at the steps 119 and 122) and X<T (Yes at the
step 124), the routine goes to a step 126 since the output power of
the driving system is excessive. At the step 126, the CPU changes
the present lower geared shifting characteristic to the normal
characteristic. On the other hand, if the present gear range
shifting characteristic is in the normal shifting characteristic at
the step 122 (Yes) but if X<T at the step S123 (Yes), the
routine goes to a step 128 in which the CPU changes the present
normal characteristic to the higher geared shifting characteristic
since it means that the output power is still excessive. It is
noted that if the present gear range shifting characteristic is in
the lower geared shifting characteristic at the steps 119, 122 and
if X>T (No) at the step 124, the routine goes to a step 125 to
determine whether X<<T (the difference between X and T is too
large to exceed the predetermined width). If Yes at the step 125,
the routine goes to a step 127 in which the lower geared shifting
characteristic is left unchanged since the present running
condition is on an emergency run on an ascending slope or in an
abrupt acceleration.
Next, at a step 129, the CPU determines whether the torque
converter of the automatic power transmission 28 is in the
locked-up state. If the torque converter is in the locked-up state
and X>T (Yes) at a step 133, the routine goes to a step 134 to
release the lock-up state of the torque converter so as to function
the torque amplification factor by means of the torque converter.
If the torque converter is not in the locked-up state (No) at the
step 129, the routine goes to a step 130 in which the CPU
determines whether the vehicle speed detected by a vehicle speed
sensor (S) indicates higher than a predetermined speed. If Yes at
the step 130, the routine goes to a step 131 in which the CPU
determines whether X<T. If Yes at the step 131, the routine goes
to a step 132 in which the CPU outputs a command signal to the
automatic power transmission 28 to lock up the torque converter. In
other cases, the routine is ended.
In the driving force controlling apparatus in the first embodiment,
the driving force at a vehicular passing point several seconds
after the present position is estimated so that the settings of the
driving characteristics of the engine 27 and automatic power
transmission 28 are adjusted in anticipation. Thus, the vehicular
driver is not aware of the delay in operation for the settings
which require considerable times to operate the shifting of the
control modes and shiftings of the gear range shifting
characteristics. Since the driving force several seconds after the
present passing point can be derived relatively from the present
actual driving force and the anticipated road gradient difference,
it is not necessary to measure the parameters contributing largely
to the running resistance such as the number of vehicular
occupants, engine's characteristic variation due to the aging
effect, the atmospheric pressure, and road wheel wear-out
condition. In addition, since the anticipated distance to the
estimated position is varied according to the running road
situations and, when the vehicle approaches to the traffic
intersection, the more future anticipation of the estimated
position is temporarily halted until the forward direction is
ascertained, the possibility of the advance control of the driving
force due to an erroneous forward direction is extremely reduced.
Furthermore, since the driving forces are estimated and are
averaged (for example, using the moving average) at the plurality
of positions from among the anticipated distances of the estimated
positions about 100 meters ahead of the present positions, the
estimation accuracy of the driving force can be higher than those
case derived at a single estimated position and the number of times
changes in the settings of the driving characteristics of the
engine and automatic power transmission are carried out can be
minimized.
It is noted that the first embodiment is not limited to the lock-up
torque converter equipped automatic power transmission 28 but is
applicable to a continuously variable transmission (for example,
CVT). Although, in the first embodiment, the driving force is
estimated on the basis of height data derived from the electronic
road map 12 as described above, the gradient data may be utilized
in place of the height data. The gradient means the height
variation per the run at a unit length of distance so that the
height data are derived by accumulating the gradients with a
predetermined point of place as a reference. In this sense, the
height is replacable with the gradient. Although in the
above-described first embodiment the height is used, the height may
be changed to the gradient since the height is calculated by the
gradient multiplied by the running distance.
It is also noted that the structure of FIG. 2 is commonly
applicable to those of the other embodiments including second
through eighth embodiments. The functions in the respective
embodiments are individually achieved according to the selections
of the various sensors S, utilizing methods of the memory unit 29,
and the content of the driving force control program interrupting
the navigation processing program by means of the arithmetic
operation unit 23. Furthermore, if, in the apparatus structure of
FIG. 2, the engine 27 is replaced with a steering characteristic
driving block and the automatic power transmission 28 is replaced
with a suspension damping force switching block, it is possible to
perform a vehicular body anticipation control of a vehicular body
performance, as described in a Japanese Patent Application First
Publication No. Heisei 2-48210. In this case, the steering
characteristic and suspension damping force characteristic can be
switched in anticipation of a road surface condition at the
estimated position of the vehicle.
(Second Embodiment)
FIGS. 8A shows a second preferred embodiment of the driving force
controlling apparatus according to the present invention.
FIG. 8B shows an explanatory view of added quantity (variable) of a
driving force margin.
Although in the first embodiment the required driving force f(x)
for the vehicle to run at an estimated interval of distance is
calculated, an operation such as an abrupt acceleration based on a
free intention of the vehicular driver is not taken into
consideration of deriving the value of the required driving force.
Hence, if the fuel consumption is suppressed with the estimated
driving force f(x) derived at maximum, the vehicle driver tends to
doubt about the insufficient engine output power for coping with a
sudden acceleration by the vehicle driver. To prevent such a
vehicular driver doubt of the engine output power, in the second
embodiment, the estimation of the driving force with driving force
margin added to the required driving force for the vehicular run is
carried out.
It is noted that since the same reference numerals as those recited
in the first embodiment designates the corresponding elements in
the second embodiment, the detailed description of the same
reference numerals will be omitted here.
In FIG. 8A, the running resistance measuring block 14 measures the
actual running resistance on the basis of the output signal derived
from the torque sensor S1. The running road estimating block 13
derives the present position of the vehicle, estimates the position
along the running route of travel 100 meter ahead of the present
position, and searches various kinds of information including
height data related to the present position and the estimated
position from the electronic road map 12. These information (height
data) and the result of the estimation of the estimated position
are transmitted to the running resistance measuring block 14, a
driving force margin calculating block 17, and a driving force
predicting block 15B. The driving force margin calculating block 17
determines a level of the driving force margin on the basis of the
output condition of the opening angle sensor S2 and the kinds of
roads.
The level of the driving force margin to be added to the required
driving force to run the vehicle is dependent on the condition of
the running road and driving tendencies that the vehicle driver
naturally has.
For example, when the vehicle runs on a freeway, there is a high
possibility of the vehicle driver passing another vehicle ahead so
that the vehicle driver makes a feeling that this vehicle becomes
failure in acceleration during the passing the other vehicle ahead
unless a considerably large driving force margin is secured. On the
other hand, in a case where the vehicle follows the preceding
vehicle with a constant intervehicle distance on the same traffic
lane of a regional road or street, it is not required to have so
large driving margin. In addition to the driving margin dependent
upon the kinds of roads and vehicular environmental situation, it
is necessary to consider the driving characteristic of the driver.
For example, the vehicle driver whose numbers of times the passing
the other vehicle ahead is carried out is less even on the freeway
does not, in general, tend to try an abrupt passing of the other
vehicle ahead on the other kinds of roads.
The driving force margin calculating block 17, at first, determines
one of the kinds of roads on which the vehicle is presently running
(for example, freeway, mountain road) during the run of the vehicle
which is transferred from the running road estimating block 13B and
which is searched from the electronic road map 12. For example, the
kinds of roads are roughly classified into the freeway, general
road, congested traffic road, and the mountain road. In addition,
the driving force margin calculating block 17 stores and determines
the number of traffic lanes on the same road in the run of the
vehicle and differentiate the driving force margin according to the
kinds of roads in run and the numbers of traffic lanes. The
classification of the kinds of roads and the number of traffic
lanes are stored into a recording medium (CD-ROM) of the electronic
road map 12 as attribute information to the road map information.
For example, in the case of the freeway, the driving force margin
.DELTA.f(X) is 50% with respect to the driving force f(x). In the
case of the congested traffic road, the driving force margin is 20%
with respect to the driving force f(x). The percentage values of
these driving force margins are derived empirically and are
mapped.
The driving force margin calculating block 17 samples an analog
signal input from the acceleration opening angle sensor S2 at a
predetermined timing so as to derive a standard deviation of an
accelerator operation for each unit of time. The large standard
deviation corresponds to the large-degree repetitive operations on
the accelerator. Since a high possibility of generations in abrupt
accelerations at a high frequency is present with the large numbers
of times the accelerator operations carried out by the driver, the
large driving force margin is previously set by which the abrupt
accelerations can be handled, as shown in FIG. 8B. The small degree
of the standard deviation means that there is a low possibility of
the future large acceleration operations by the driver so that the
driving force margin is narrowed. It is noted that the standard
deviation of the accelerator operation may be replaced with a
standard deviation of a vehicle speed or engine revolution speed.
The driving force margin calculating block 17 transmits a maximum
value of the driving force margin derived by the several methods
described above.
The driving force predicting block 15B adds the driving force
margin .DELTA.f(x) derived by the driving force margin calculating
block 17 to the driving force f(x) based on the actual running
resistance estimated in accordance with the procedure of the first
embodiment to derive the required driving force FF(x).
The required driving force FF(x) is defined as the required driving
force several seconds after the time at which the vehicle has
passed the present position. The driving system controlling block
16B adjusts the setting of the engine air/fuel mixture ratio
controlling modes, gear range shifting characteristic of the
automatic power transmission, and the locked-up state of the torque
converter using thus derived required driving force FF(x). The
driving system controlling block 16B changes the setting of the
air/fuel mixture ratio control modes and gear range shifting
characteristics of the automatic power transmission several seconds
before reaching to the estimated position so that the fuel
consumption is suppressed in a range which can cope with the
required driving force FF(x).
In the driving force controlling apparatus in the second embodiment
described above, the driving force margin is defined from the
situation in roads and the driving characteristic of the vehicular
driver and the anticipation control is carried out on the basis of
the required driving force including the driving force margin.
Hence, with the driving force control to save the fuel consumption
achieved, the problem of a deterioration in the driving
characteristic due to an unintended acceleration can be solved. In
addition, some drivers hardly make the abrupt acceleration of the
vehicle. For such drivers as described above, the set driving force
margin becomes automatically be reduced. With the driving force at
the position x set to a small value, the reduction of the fuel
economy due to the abrupt acceleration can be prevented.
FIG. 9 shows an operational flowchart for setting the driving force
margin in a modification of the second embodiment. In the
modification of the second embodiment shown in FIGS. 9, and 10, the
driving force margin is derived from the driving situation of the
vehicle driver (namely, the opening angle of the engine throttle
valve) and the running speed of the vehicle, not rested on the
searched information from the electronic road map 12.
It is noted that the whole flowchart of FIG. 9 is interrupted in
series with the flowchart of FIGS. 5 and 6 of the first
embodiment.
It is also noted that a vehicle speed sensor S3 is connected to the
driving force margin calculating block 17C in parallel to the
accelerator opening angle sensor S2, as shown in FIG. 10. The
vehicle speed sensor S3 measures an ever-changing velocity of the
vehicle with respect to the ground.
As shown in FIG. 9, when this interrupt routine is started, the CPU
calculates values of the standard deviations of accelerator
operations and vehicular velocities at a step 135. At a step 136,
the CPU determines whether the standard deviation value of the
accelerator operations is relatively large (this means that the
present driver has a high possibility of trying the abrupt
acceleration). If it is large (Yes) at the step 136, the routine
goes to a step 136.
On the other hand, if the standard deviation of the accelerator
operations is small (No at the step 136), the routine goes to a
step 137 in which the CPU determines whether the standard deviation
value of the vehicle velocities, in turn, is relatively high. If
the standard deviation of the vehicle velocities is relatively high
(large) (this means that the repetitions of accelerations and
decelerations are carried out). If the value of the standard
deviation is high (large) (Yes) at the step 137, the routine goes
to a step 140. On the other hand, in a case where the standard
deviation of the vehicle velocities is small (No) at the step 137,
the routine goes to a step 138 in which the CPU determines whether
the vehicle velocity is relatively high.
If the vehicle velocity is high at the step 138, this means that
the vehicle is running on the freeway and there is a high
possibility of requiring an abrupt high power due to execution of a
passing through another vehicle ahead and the routine goes to the
step 140.
At the step 140, the CPU sets the driving characteristic of the
engine to the stoichiometric control to reach to the stoichiometric
air/fuel mixture ratio of the engine 27.
Thereafter, the routine goes to a step 139 in which the moving
average value of the presently generated driving force (generated
driving force T) is compared with the moving average value
(estimated driving force X) of the estimated driving force at the
forward interval of distance. If X>>T (the estimated moving
averaged driving force X is considerably larger than the generated
moving averaged driving force T) at the step 139, the routine goes
to a step 141 in which the engine 37 is in the stoichiometric
control mode and the gear range shifting characteristic of the
automatic power transmission 28 is changed to the normal
characteristic so as to take a higher priority for securing the
output power.
In the modification of the second embodiment, the driving force
margin is calculated from the combination between the output
signals of the accelerator opening angle sensor S1 and the vehicle
speed sensor S3. Thus, it is not necessary to read in the kinds of
roads and the number of the traffic lanes on the same road from the
electronic road map. A calculation burden on the driving force
margin calculating block 17 is relieved by the reduced quantity of
information handled. It is noted that the driving force margin may
be estimated from only the standard deviation of the accelerator
operations.
Under a supposition that the presently generated driving force
would be required in the near future, with the estimated driving
force f(x) at the position x replaced with the presently generated
driving force f(P), the driving force margin may be set with the
driving force f(P) multiplied by a constant representing a width of
the acceleration upper and lower limits. Thus, the estimation of
the driving force margin in the second embodiment is established
without the presence of the electronic road map 12. For example, as
shown in FIG. 8B, the standard deviation of the accelerator
operations and its corresponding addition quantity of the driving
force margin are mapped in a form of table and the addition
quantity of the driving force margin is estimated immediately from
the standard deviation of the accelerator operations. Suppose that
a rate of the driving force margin recited in the table is .phi.
and the required driving force derived with the driving force
margin added is FF(x).
(Third Embodiment)
FIG. 10 shows a third preferred embodiment of the driving force
controlling apparatus according to the present invention.
The structure of the driving force controlling apparatus shown in
FIG. 10 is almost the same as that in the first embodiment.
However, in the third embodiment, a driving system total
controlling block 16C is added to carry out a more precise
allocation of the settings for the respective situations.
The driving force margin calculating block 17C calculates the
driving force margin on the basis of output states of the
accelerator opening angle sensor S2, the vehicle velocity sensor
S3, and the engine revolution speed sensor S4 without use of the
searched information from the electronic road map 12.
The driving force predicting block 15C derives the required driving
force f(x) by adding the driving force at the anticipated point of
place x estimated from the present driving force in the same
procedure as the first embodiment to the driving force margin
derived by the driving force margin calculating block 17C. The
driving system total controlling block 58 is provided with a map
defined what mode of control should be carried out for the required
driving force f(x) at the anticipated point of location x. The
driving system total controlling block 16C in principle sets the
enlarged air/fuel mixture ratio of the engine, namely, the lean
burn control mode provided that the required driving force f(x) is
below a predetermined value. On the other hand, if he required
driving force is larger than the predetermined value, the driving
system total controlling block 16C sets the engine to the
stoichiometric air/fuel mixture ratio control mode. The driving
system total controlling block 16C sets the high geared
characteristic to the automatic power transmission if the required
driving force f(x) is relatively smaller and sets the lower geared
shifting characteristic thereto if the required driving force f(x)
is relatively large.
It is noted that if the setting of the respective control items are
mechanically carried out only by a simple magnitude relationship
between the presently generated driving force which is being
generated at present, the estimated required driving force, and the
predetermined constant, some problems under several special
situations would occur. Hence, it is necessary to allocate to a
special setting for such special situations.
In addition, if the settings of a plurality of control items are
simultaneously changed, a response of the vehicle to the input of
the accelerator operation is abruptly changed so that the vehicle
driver may confuse this abrupt change in the response. Hence, the
timings of the switching operations for the respective control
items are adjusted so that a continuity in the driveability is
required to be secured. The driving system total controlling block
16C maps a combination of the setting contents of the plurality of
control items so as to accommodate to the individually distinct
situations.
In addition, the driving system total controlling block 16C adjusts
the switching order and switching timings so as to minimize a
discontinuity feeling of the driving sense along with the
switchings in the respective control items.
This function is effective in a case where the driving margin is
set according to the kinds of roads and individually different
situations of the drivers as described in the second embodiment.
The driving system total controlling block 16C causes the following
settings to be allocated to for the remarkably increased individual
situations of the combinations:
(1) When the standard deviation of the present accelerator
operations is relatively large, the engine setting is carried out
such that the stoichiometric air/fuel mixture ratio control mode is
carried out at the point of place denoted by x. The large standard
deviation of the accelerator operations means that such a situation
that the driver requires the large driving force and requires, in
turn, no large driving force occurs. In this situation, a high
possibility of a strong depression of the accelerator pedal even at
the future interval of distance to be traveled. In such a situation
as described above, if the engine is placed in the lean burn
control mode, the increase in the driving force due to the strong
depression on the accelerator pedal during the acceleration is
small and the margin on the depression angle of the accelerator
pedal becomes reduced. Thus, the vehicle driver feels that this
vehicle fails to accelerate or the vehicle is difficult to be
accelerated.
(2) In a case where both values of the standard deviations of the
present velocities of the vehicle and of the accelerator operations
are smaller than the predetermined value preset empirically, the
engine air/fuel mixture ratio control is placed in the lean burn
control mode. The small standard deviation of the accelerator
operations is deemed to be such that the vehicle driver does not
carry out frequently the accelerations and decelerations and the
small standard deviation of the vehicle velocities is deemed to be
such that the vehicle runs at the cruise speed and the cruise speed
is maintained. In this case, since the possibility of the abrupt
acceleration is low in the near future of travel, the engine
air/fuel mixture ratio is changed in the lean burn control so that
the fuel consumption is suppressed.
(3) In a case where the standard deviation of the present vehicular
velocity variations is small and the velocity is relatively high,
the combination in the lean burn control mode of the engine
air/fuel mixture ratio control and higher-geared shifting
characteristic is adopted. The small velocity variation and
high-speed run are deemed to be such that the vehicle runs on the
freeway and the number of times the passing of the other vehicles
ahead is carried out is extremely less. In this situation, even
though the extremely reduced fuel consumption is brought out due to
the combination of the settings of the lean burn control and
higher-geared characteristic, other disadvantages cannot occur.
(4) On the contrary, if the standard deviation of the present
vehicle velocity variations is large and the vehicle speed itself
is large, the settings of the driving characteristics of the engine
and automatic power transmissions are such that the combination of
the stoichiometric control and higher-geared shifting
characteristics. The high velocity of the vehicle and the large
variation in the vehicle velocities mean that the vehicle is
running on the freeway and the passings of the other vehicles ahead
are repeated at the freeway. Since the engine driveability is
deteriorated due to the adoption of the lean burn air/fuel mixture
ratio control mode, the driveability is secured by the
stoichiometric air/fuel mixture ratio control and the higher geared
shifting characteristic can bring out the higher air/fuel mixture
ratio.
(5) when the moving average value of the presently generated
driving force (generated driving force T) is compared with the
moving average (estimated driving force X) of the estimated driving
force at the forward direction interval of distance, the lean burn
control mode is immediately halted if X>T during the lean burn
control mode so as to avoid the insufficient acceleration ability
at the future ascending slope gradient.
(6) If the result of comparison between the generated driving force
T and estimated driving force is X>>T, the automatic power
transmission gear range shifting characteristic is transferred to
the normal characteristic from the higher geared range shifting
characteristic when the higher geared range shifting characteristic
is being carried out and is transferred to the lower geared
shifting characteristic when it is in the normal characteristic in
addition to the halt of engine lean burn control mode. Thus, such a
situation that the insufficient, acceleration characteristic of the
driving system can be avoided when the vehicle ascends a steep
gradient slope.
(7) On the other hand, if the estimated driving force X is smaller
than the presently generated driving force T by the predetermined
value (X<T), the vehicle driving characteristic needs to be
transferred to the normal characteristic from the higher geared
range shifting characteristic in the automatic power transmission
if the present geared shifting characteristic is the higher geared
mode and to be transferred to the lower geared range shifting
characteristic if the present geared shifting characteristic is the
normal characteristic mode. The condition of X<T means that the
vehicle is to run on a descending slope in the near future of the
route of travel. In this case, it is important for an engine
braking to be easy to be effective in the driving force control.
Therefore, n this case, the gear range shifting characteristic of
the automatic power transmission needs to be selected in the normal
characteristic or in the lower geared range shifting
characteristic, both geared range shifting characteristic being
effective in the engine braking in place of the higher geared range
shifting characteristic which is not effective in the engine
braking.
(8) If the present gear range shifting characteristic is in the
higher geared range shifting characteristic and the future
estimated driving force X is larger than the generated driving
force (X>T), the geared range shifting characteristic is
switched to the normal characteristic.
(9) If the present gear range shifting characteristic is in the
normal characteristic and the future estimated driving force X is
larger than the presently generated driving force T (X>T), the
geared range shifting characteristic in the normal mode is switched
to the lower geared shifting characteristic.
(10) If the present gear range shifting characteristic is in the
lower geared shifting characteristic and the future estimated
driving force X is smaller than the presently generated driving
force T (X<T), the present lower geared range shifting
characteristic in the automatic power transmission is switched to
the normal characteristic.
(11) If the present geared range shifting characteristic is in the
normal characteristic and the future estimated driving force is
smaller than the presently generated driving force (X<T), the
geared range shifting characteristic is switched to the higher
geared range shifting characteristic.
(12) If the engine is presently in the lean burn control mode and
the future estimated driving force X is larger than the future
estimated driving force T (X>T), the lean burn control mode is
halted and is transferred to the stoichiometric air/fuel mixture
ratio control mode.
(13) If the engine is presently in the stoichiometric air/fuel
mixture ratio control mode and the future estimated driving force X
is smaller than the presently generated driving force T (X<T),
the engine air/fuel mixture ratio control mode is transferred to
the lean burn air/fuel mixture ratio control mode.
(14) If the torque converter of the automatic power transmission is
presently in the lock-up engaged and the future estimated driving
force X is larger than the presently generated driving force T
(X>T), the lock-up state is released.
(15) If thee torque converter is presently in the lock-up released
state, the present vehicle velocity is higher than the
predetermined velocity value, and the future estimated driving
force X is smaller than the presently generated driving force T
(X<T), the lock-up is engaged.
The respective comparison values and switching values on tables of
(1) through (15) are defined by the experiment. In addition, in the
tables of (1) through (15), both of the moving average value of the
presently generated driving forces (generated driving force T) and
the moving average value of the estimated driving forces at the
forward interval of distance (estimated driving force X) are used,
the same control may be carried out on the basis of the two
instantaneous values of the generated driving force at the
vehicular present position and the estimated driving force at the
estimated single position.
In the driving force control apparatus of the third embodiment, the
so-called total control is adopted. Thus, even if the items to be
controlled are increased and the great numbers of possible settings
in each one item are present, an appropriate and flexible setting
is possible. In addition, since the timings at which the settings
for the engine and automatic power transmission are mutually
adjusted, the continuity in the vehicle response is secured for the
operation by the vehicle driver and such a situation that an abrupt
change in the acceleration response of the own vehicle to the
depression angle of the accelerator pedal does not occur.
Furthermore, in a case where such a situation that the engine
braking becomes effective during the vehicular run on the
descending slope, this situation being a setting outside of a basic
principle of a light load with the fuel economy, the effective and
appropriate setting is possible.
(Fourth Embodiment)
Before explaining the vehicular driving force controlling apparatus
in a fourth embodiment, FIGS. 18A and 18B show explanatory views
for explaining problems to be solved in a case where the vehicular
driving force controlling apparatus according to the present
invention estimates the future position of the own vehicle several
seconds after the time at which the vehicle is running at present
position. FIG. 18A shows a traffic intersection and FIG. 18B shows
a tollgate.
As in the case of FIG. 18A, when the vehicle is running on the set
route of travel and is about to reach to the traffic intersection,
such a problem as along which of the branched roads from the
intersection the vehicular driving force controlling system should
try to search the estimated position of the vehicle and estimate
the driving force occurs. In the previously described first
embodiment, the anticipation of the estimated driving force is
upheld until the vehicle has passed the intersection as described
with reference to FIG. 4. However, in this method, the anticipation
control on the basis of the estimated driving force cannot be
advanced any more if a plurality of intersections are present for
each interval of distance of several ten meters in front of the
vehicle. In the fourth and fifth embodiments of the vehicular
driving force controlling apparatus, to which one of the branched
roads the vehicle is to be forwarded is determined at the position
before the intersection and the estimated point of road is advanced
to the determined branched road.
On the other hand, in a case where the vehicle is running on the
freeway and the vehicle is to be reached to a position in front of
a tollgate as shown in FIG. 18B, a practical anticipation control
cannot be achieved if the driving force is estimated only from the
gradient information of the road located at the forward position of
the vehicle. This is because the vehicle driver always stops the
vehicle at the tollgate and, thereafter, restarts the vehicle. This
situation is also applicable to the cases where a road junction is
present, a place in front of a traffic lane change inhibiting lane
is present, a traffic lane is limited due to a long term
construction of road. Furthermore, in cases where the vehicle runs
on a road having a remarkably varying degree of congestion
according to a traffic situation, the vehicle runs on roads whose
widths are remarkably and abruptly varied or roads whose
frequencies of radii of curvatures are remarkably and abruptly
varied geographically, and the vehicle runs on a junction directly
connected from the freeway to a general road, it is not possible to
make optimum settings for the engine and automatic power
transmission only according to the forward road gradient
information. Hence, in sixth and seventh embodiments, the settings
of the driving characteristics of the engine and automatic
transmission determined according to the gradient information are
practically corrected utilizing the information stored by the
vehicle itself and in the form of data base.
Furthermore, an erroneous estimation of the driving force is not
only due to such external factors as described above but also due
to a change in mind of the vehicular driver himself. For example,
when the driver has made up his mind of changing the destination
due to his remembrance of a thing left behind during the driving
and the driver has made the vehicle U-turn, the driver has abrupt
left or right turn after an abrupt braking, or makes a direction
inversion through a large angle of steering change, the vehicular
driving force controlling apparatus would erroneously estimate the
set route of travel. As one of the other cases, as soon as the
vehicle is passed by a following vehicle, there are often such
drivers that the attitude of the driver is abruptly changed and the
driver boldly tries to start the passing the preceding vehicle
ahead, repeating abrupt accelerations and abrupt stops which are
quite different from the driving pattern from now on. In such cases
as described above, if the setting contents are as described above,
the driver doubts the insufficient output power of the vehicle and
worsened response characteristic of the vehicle. Hence, in an
eighth embodiment, the settings of the engine and automatic power
transmission determined according to the gradient of the road are
practically corrected when the driver's mental state is
changed.
FIGS. 11A and 11B show explanatory views of the vehicular driving
force controlling apparatus in the fourth embodiment. FIG. 11A
shows the functional block diagram of the driving force controlling
apparatus in the fourth embodiment. FIG. 11B shows the explanatory
view for explaining a technique of estimating the anticipated
(estimated) position of the vehicle to be passed when the estimated
position is jumped over the branch point (intersection). In the
fourth embodiment, the driving force controlling apparatus
automatically determines which one of the branched roads the
vehicle is to be forwarded at any one of branch points on the basis
of a designation to which the vehicle is to reach set by the
vehicle driver before the start of travel of the vehicle. The same
reference numerals shown in FIG. 11A designate corresponding
elements used in the first embodiment.
The running resistance measuring block 14 measures an actual
running resistance on the basis of an output signal of the torque
sensor S1. The running road estimating block 13D derives the
present position of the own vehicle in the road map stored in the
electronic road map 12 according to the latitude and longitude of
the own vehicle derived in the own vehicle position specifying
block 11. In addition, the estimated position of the own vehicle
several seconds after the time at which the vehicle is at the
present position is derived by the running road estimating block
13D and the information of height between the present position and
estimated position of the vehicle is transmitted from the running
road estimating block 13D to the running resistance measuring block
14 and the driving force predicting block 15D. The driving force
predicting block 15D corrects the actual running resistance on the
basis of the height difference between the present position and the
estimated position several seconds after the time at which the
vehicle is at the present position and estimates the required
driving force at the estimated position. The driving system (power
train) controlling block 16D predictively changes the settings of
the engine and automatic power transmission on the basis of the
estimated required driving force so as to suppress the fuel
consumption as low as possible in the range which satisfies the the
exerting of the estimated required driving force, thus maintaining
the purification of the exhaust gas. The running road estimating
block 13D estimates the forward direction of the own vehicle at the
branch point by referring to the set destination in prior to the
vehicle start so that the estimated position after several seconds
after the time at which the vehicle is at the present position in
the estimated forward direction.
It is noted that a destination inputting block 18 through which the
vehicle driver input the destination of the travel prior to the
start of the vehicle. An input format of the destination at the
destination inputting block 18 is, for example, such a format that
a road image requested to be called on the monitor screen of the
vehicular navigation system is scrolled to search for the road map
image including the set destination and the destination is set
through a finger touch input of the destination on the monitor
screen. The destination may be inputted through a keyboard
operation using the latitude, longitude, and direction of the
destination.
In FIG. 11B, suppose that the own vehicle is running at the
position P before the vehicle is to pass through the intersection
G.
The running road estimating block 13D of the driving force
controlling apparatus anticipates the gradient of the position x 60
meters through 100 meters ahead of the present position and
estimates the ever-changing driving forces based on the gradient
variations at the interval of distance from the present position up
to the position x. It is noted that when the vehicle approaches the
intersection G so that the position x has reached to a center of
the intersection G, the running road estimating block 13D
determines which one of the branched road directions from the
intersection G the vehicle should be forwarded using the following
way.
That is to say, a vector xy connecting the center position x on the
intersection G with the previously set destination y is, at first,
calculated. Thereafter, position coordinates of three positions a,
b, and c which are one kilometer ahead of the center position x
along the respective branched roads are read from the electronic
road map 12 to calculate three vectors xa, xb, and xc. Then, the
running road estimating block 13D calculates angles of the three
vectors xa, xb, and xc with respect to the vector xy, compares with
one another, and estimates that one of the vectors whose calculated
angles which gives minimum is the estimated branched road forward
direction. In the case of FIG. 11B, since the angle of the vector
xb to the vector xy gives the minimum, the branched road in the
direction of b is selected. Thereafter, in the same way as in the
first embodiment, the gradient at the position x 100 meter ahead
along the branched road from the position P to the b direction is
anticipated so that the required driving force is estimated and the
settings of the engine and automatic power transmission are
adjusted.
According to the driving force controlling apparatus in the fourth
embodiment, the anticipation after the passage through the
intersection G before the arrival at the intersection is carried
out so that the required settings of the engine and automatic power
transmission are started. Hence, even in a case where the own
vehicle runs at a considerably high speed, the vehicle driver is
not aware of the control delay and the insufficient power due to
the control delay after the vehicle has passed the intersection G.
It is noted that in a route guidance type navigation system in
which an optimum route of travel to the destination is recommended
to the vehicle driver on the basis of the information from the
normal navigation system and driving support system at a road side
with the destination previously input, the anticipated road point
can be set along the recommended running route. The driving support
system at the road side is a system providing road information for
vehicles from a great number of small transmission stations
arranged long roads. However, although some drivers tend not to
follow the recommended running route, this problem will be
described in the foregoing seventh embodiment.
In addition, in a case where information sources installed at sides
of roads can be utilized as in the case of VICS, a system may be
considered such that a congestion informations, accident
information, and lane limitation information are detected and a
relationship between the detected information and the vehicle
running route is determined so that a correction of the running
route is automatically executed avoiding inconvenient roads. In
this case, the anticipation of the estimated position is carried
out along the corrected running route.
(Fifth Embodiment)
FIGS. 12A and 12B show a fifth preferred embodiment of the
vehicular driving force controlling apparatus according to the
present invention.
FIG. 12A shows the functional block diagram of the fifth embodiment
according to the present invention.
FIG. 12B shows an explanatory view for explaining an estimation of
future position as the estimated position of the vehicle when the
estimated position is jumped over the intersection G in the case of
the fifth embodiment.
In the fifth embodiment, an intention of the driver to select one
of the branched roads from the intersection G is detected through a
winker (direction indicator) and the automatic determination of
which one of the branched roads the vehicle is to be forwarded at
the branch point is carried out. The same reference numerals as
shown FIGS. 12A and 12B designate corresponding elements of the
first and fourth embodiment described above.
In the fifth embodiment shown in FIG. 12A, the running road
estimating block 13E derives the present position of the own
vehicle at the road map stored in the electronic road map 12 on the
basis of the output information of the own vehicle position
specifying block 11 and derives the estimated position of the
vehicle located several tens through 100 meters ahead of the
present position on the basis of the derived present position of
the vehicle. The running road estimating block 13E estimates refers
to output states of a direction indicator (winker) sensor S5, a
brake sensor S6, accelerator sensor S7, and vehicle speed sensor S8
so as to estimate the forward direction of the vehicle at the
branch point (a forward direction toward which the vehicle is
desired to forward by the vehicle driver) and moves the estimated
position several seconds after the time at which the vehicle is at
the present position to the derived forward direction. The
direction indicator S5 outputs a signal corresponding to a
distinction between a left turn or right turn operated by the
driver on the winker. The brake sensor S6 detects a presence or
absence of a depression operation on a vehicular brake pedal. The
accelerator sensor S7 detects an increase or decrease in a
depression quantity of the accelerator pedal. The speed sensor S8
detects a wheel (road wheel) revolution speed and outputs a digital
pulse train signal per second whose pulse number corresponds to a
velocity of the vehicle with respect to the ground.
In FIG. 12B, suppose that the vehicle is running on a point P1
placed in front of the intersection G. The running road estimating
block 13E estimates the ever-changing driving forces based on the
variations in the gradients for the interval of distance up to the
anticipated road point x in anticipation of the gradient of the
position x 60 meters through 100 meters ahead of the present
position at which the estimation of the road point is carried out.
If the vehicle, as shown in FIG. 12B, approaches the vehicle at the
intersection G having three directed branched roads A, B, and C and
the anticipated road point x is reached to the center position of
the intersection G, the running road estimating block 13E fixes the
road point x to the center position of the intersection unless the
forward direction at the intersection G is ensured at this time.
Then, if the vehicle driver operates the winker S5 or if a straight
run is assured and determined according to the output state of the
speed sensor S8, the normal anticipation of the future road point x
is resumed with the estimated point of road x advanced to the
determined forward direction branched road. The running road
estimating block 13E continuously reads the height of the
anticipated road point x a predetermined distance ahead of the
center position of the intersection G from the electronic road map
12. Furthermore, during the run of the vehicle to approach to the
intersection G, the running road estimating block 13E continues to
read the heights of the estimated positions x. Thereafter, if the
vehicle driver operates the winker to indicate either turn of left
or right, the estimated points of roads x are moved to one of the
roads in the turned direction.
In the case of FIG. 12B, since the winker S5 starts to indicate the
vehicle's left turn at the time at which the own vehicle has run on
the position of P in front of the intersection G, the branched road
A is selected as the future forward direction and the point of road
for the anticipation of the height is moved to a position xa which
is a predetermined distance ahead of the position x supposing the
left-sided road from the position x. The driving force predicting
block 15E calculates the gradient from the height information read
out from the electronic road map 12 so as to estimate the required
driving force.
The running road estimating block 13E monitors the running speed of
the own vehicle and the depression quantity (angle) of the
accelerator pedal in parallel to the direction indicator S5. Thus,
if a depression release of the accelerator pedal and/or
deceleration of the vehicle is not present during the vehicle run
approaching the intersection G, one of the branched roads having a
highest degree of coincidence between each of vectors drawn from
the center position of the intersection G to the respectively
branched roads A, B, and C and a vector indicating the velocity of
the vehicle is selected and the estimated position x is advanced to
the selected branched road. Similarly, the running road estimating
block 13E monitors the running velocity of the own vehicle and
whether the brake pedal is depressed. Hence, if the vehicle is
decelerated and/or its brake pedal is depressed, the estimated road
point x is moved to a selected one of the branched road whose
degree of coincidence between the corresponding one of the vectors
drawn from the point of x at the intersection G to the respective
branched roads A, B, and C to the vector indicating the direction
of the velocity is lowest. Furthermore, if the running road
estimating block 13E determines that a width of a road segment at
the road to be branched from the intersection G is extremely
different from the road on which the vehicle has run from the
information such as the kinds of roads searched from the electronic
road map 12, for example, the width of the roads is changed from a
one-traffic lane road to three-traffic lane road, the running road
estimating block 13E selects the branched road whose width is wider
when the outputs of the speed sensor S8 and the accelerator
depression responsive sensor S7 if no presence in the velocity
variation and an acceleration is observed at the time during which
the vehicle is to be reached to the intersection G and sets the
anticipated point of road x.
In the driving force estimating block in the fifth embodiment, -the
determination of one of the branched roads for the vehicle to be
forwarded can be assured rather than the technique in the fourth
embodiment.
Hence, if there is a low possibility of executing the erroneous
driving force control with the erroneous selection of the branched
roads. In addition, the vehicle driver does not feel the
insufficient output power of the vehicular driving system in a case
where a steep ascending slope is present on the selected branched
road immediately after the passage through the intersection G. The
direction indicator S5, the brake sensor S6, the accelerator pedal
depression sensor S7, and the speed sensor S8 constitute such means
for detecting the operation content of the vehicle driver through
the input operating variables of the vehicle and identifying the
forward direction of the own vehicle at the branch point of road.
It is noted that each output of the brake responsive sensor S6, the
accelerator depression responsive sensor S7, and the speed sensor
S8 is secondarily referred to for to the output of the direction
indicator S5. The processing of the fifth embodiment is possible if
either or all of the brake responsive sensor S6, accelerator pedal
responsive sensor S6, the speed sensor S8 are not always referred
to. This is because if the direction indicator S5 is operated, its
indicating direction can be used to determine the forward direction
at the intersection G. In addition, the straight run at the
intersection can be determined in the vase where the velocity is
not so largely reduced with no operation of the direction indicator
S5 and/or no operation on the brake pedal even if the vehicle
approaches and enters the intersection G or in a case where some
degree of acceleration of the vehicle is carried out at the
intersection G.
(Sixth Embodiment)
FIGS. 13A and 13B show a sixth preferred embodiment of the
vehicular driving force controlling apparatus.
FIG. 13A shows the functional block diagram of the vehicular
driving force controlling apparatus in the sixth embodiment.
FIG. 13B shows an explanatory view for explaining a recorded state
in a rewritable electronic road map.
In the sixth embodiment, a past running state is recorded on the
rewritable electronic road map 12F and the estimated driving force
based on the height information on the estimated position is
corrected using such a unique data base as described above.
The same reference numerals shown in FIGS. 13A and 13B as those in
the first embodiment designate corresponding elements in the first
embodiment.
The running road estimating block 13F derives the present position
of the own vehicle on the road map stored in the rewritable
electronic road map 12F using the output information of the own
vehicle specifying block 11 and derives the estimated position of
the own vehicle several seconds after the time at which the vehicle
is at the present position and located several tens meters through
100 meter in front of the present position along the road on which
the vehicle runs. The running road estimating block 13F measures
the ever-changing running velocity of the vehicle through the speed
sensor S8 and outputs the ever-changing running velocity to a
running locus recording block 19 together with the present position
of the vehicle. Furthermore, the running road estimating block 13F
batches the information searched from the rewritable electronic
road map 12F and its own prepared information as a single file, the
single file being held therein.
The running locus recording block 19 prepares the data representing
the running state on the basis of the running velocity transmitted
from the running road estimating block 13F and updates and records
the prepared data on the ever-rewriting enabled electronic road map
12F. The data representing the running state is calculated from the
previously recorded data and the present running velocity and is
recorded in a state shown in FIG. 13B in which the search is
possible using an address indicating the position on the road
map.
It is noted that if the data representing the running state is the
gear ratio of the automatic power transmission, the running locus
recording block 19 sequentially stores the gear ratio with which
the vehicle has run on the same roads in the rewritable electronic
road map 12F. The data format is the same as in the case of the
running velocity.
The running road estimating block 13F refers to the data called
from the rewritable electronic road map 12F and identifies whether
the running state at the estimated position is predictable. If it
is predictable, this data is transmitted through the driving force
predicting block 15F to the driving system controlling block 16F.
The driving force predicting block 15F estimates the required
driving force at the estimated position in the same procedure as in
the case of the first embodiment only when the running state is
determined to be predictable. The driving system controlling block
16F corrects the settings of the engine and automatic power
transmission with reference to the past data in a case where the
running state at the estimated position is predictable.
The data representing the running state and stored in the
rewritable electronic road map 12F has a better quality whenever
the running on the same location is repeated reflecting more
appropriately--a situation that the location naturally has--not
appearing on the road map. The following control, specifically, is
executed using the past running state.
The rewritable electronic road map 12F finds out the position
specified on the road map from the output information of the own
vehicle position specifying block 11 and stores the instantaneous
velocity into a memory area corresponding to a mesh at that
location as shown in FIG. 13B.
Anyway, in a case where the vehicle is to run on a road on which
the vehicular driver has no experience of travel, the rewritable
electronic road map 12F does not function effectively since the
data is not previously stored at all. However, even if the vehicle
driver has no experience of running on such a unknown road as
described above, the vehicle data=0 is previously written into the
memory area corresponding to the unknown road during a shipment of
the vehicle for such locations as unavoidable temporary halt and
stops of the vehicle at the locations, for example, the tollgates,
grade crossings, temporary halt portions, traffic intersections
having no signals through which narrow roads are junctioned into
wide, traffic priority roads. Whenever the vehicle runs on these
locations as described above, average values between the vehicle
speed data previously written including the data written during the
shipment of the vehicle and the present vehicle velocity values are
derived so as to update the recorded contents in the memory area of
the rewritable electronic road map 12F.
In FIG. 14, when the vehicle runs at the position P on the road,
the running road estimating block 13F anticipates the height at the
position x which is away from the position P by a predetermined
distance in the vehicular forward direction from the rewritable
electronic road map 12F. The driving force predicting block 15F
carries out the ever-changing estimation of the driving force based
on the gradient variation at an interval of distance up to the
position x. At this time, the running road estimating block 13F
calculates a difference between the velocity at the present
position P and the velocity at the point P on which the vehicle has
experienced the run at the past time.
If the difference described above is extremely large, for example,
the difference is twice or more than the past running velocity, the
running road estimating block 13F determines that the present
running state is remarkably different from the state past
experienced and halts the control of the updating the data using
the past data. In addition, with the past data held in the
unchanged state, the running road estimating block 13F averages the
data so that the updating operation for the past data is
halted.
However, in a case where at each present position of the vehicle
the past velocities are all different from the present velocities,
the running road estimating block 13F determines that the velocity
would be varied at the points of locations x ahead of the present
position at generally same procedures. That is to say, at the
preceding point of location x in which the running state is at a
state wherein the past velocity is approximately zero, that
location has a high possibility of usual presence of traffic
congestion. In this case, even if the driving force controlling
block 16F determines that the height of the point of location x is
higher than the present location P of the vehicle and the ascending
slope is continued and sets the automatic power transmission at the
lower geared range shifting characteristic to prepare the large
driving force, the large driving force cannot fully be utilized
provided that the high degree of traffic congestion at the point of
location x is assured. It is preferable in terms of the vehicular
driveability and fuel economy to drop the driving force.
Therefore, in the case where the degree of coincidence between the
present velocity of the vehicle and the past velocity is high, the
driving system controlling block 16F controls the engine and
automatic transmission driving characteristics on the basis of the
past velocity of the vehicle at the point of road x read from the
rewritable electronic road map 12F in place of the required driving
force at the point of location (road) x estimated by the
anticipation of the height at the point of location x. Then, in a
case where the past velocity at the point of location x is low, the
driving system controlling block 16F selects the driving force when
the vehicle cruises in place of the driving force estimated from
its gradient.
For example, when it is determined that the past velocity at the
point of location x at the forward ascending slope is low, the
engine lean burn control mode remains unchanged for the run in the
traffic congestion and for the cruise speed run and the gear range
shift switching characteristic of the automatic power transmission
is at the higher geared range shifting characteristic in place of
the halt of the lean burn air/fuel mixture ratio control mode so as
to accommodate the ascending slope and setting of the switching
characteristic of the lower geared range shifting
characteristic.
It is noted that the information related to the driving force
generated by the vehicle, in addition to the vehicle velocity and
gear ratio of the automatic power transmission, may include the
engine revolution speed x gear position (gear ratio), output axle
torque, the variation in velocity per unit of time, a quantity of a
fuel injection into the engine commanded from an engine control
unit, or its related variable (a time duration during which fuel
injector(s) injects the fuel quantity). These variables may be
stored in the rewritable electronic road map in place of the
running velocity described above so that these variables may serve
as parameters to monitor the running state of the vehicle.
In the driving force controlling apparatus of the sixth embodiment,
road situations of a location at which the traffic stream is often
varied although it is not usual due to the reduction of the number
of traffic lanes or due to a bottle neck of the traffic stream and
of a location at which the stream of the driving is always varied
such as at the tollgate or intersection are stored, the information
of the anticipated point of the height on the basis of these road
situations is interpreted as the variation, and the controlled
characteristics of the driving system are changed so that the
reduction in the vehicular driveability due to the anticipation
control can be relieved. The rewritable electronic road map 12F can
be constituted by the combination of the CD-ROM play-back unit 22
and memory unit 29 (as shown in FIG. 2).
It is noted that the driving force predicting block 15F may further
correct the required driving force at the estimated position of the
vehicle (or at the interval of distance up to the estimated
position) in which the actual running resistance is corrected
according to the height difference between the present position and
estimated position on the basis of the predicted result. The
driving system controlling block 16F controls the engine and
automatic power transmission on the basis of the corrected required
driving force. In addition, the data to be stored in the rewritable
electronic road map 12F may be the data to estimate the running
situation of the vehicle and running pattern. The data is not
limited to the running velocity of the vehicle but may be the
information related to the driving force which is being generated
by the vehicle.
For example, the engine revolution speed and gear shift ratio of
the transmission, opening angle of the throttle valve, and running
resistance value may be stored in the corresponding memory
areas.
If the data stored in the rewritable electronic road map 12F is not
related to the vehicle velocity, the engine revolution speed and
gear shift ratio may be converted into the velocity of the vehicle,
alternatively, the opening angle of the engine throttle valve and
gear shift ratio may be converted into the velocity of the vehicle,
or alternatively the throttle valve opening angle and gear shift
ratio may be converted into the velocity of the vehicle using the
corresponding map.
(Seventh Embodiment)
FIG. 15A and 15B show a seventh preferred embodiment of the
vehicular driving force controlling apparatus according to the
present invention.
FIG. 15A shows the functional block diagram of the seventh
embodiment and FIG. 15B shows a processing flowchart of-an
evaluation block 32 shown in FIG. 15A.
In the seventh embodiment, with the past driving force state
recorded using the rewritable electronic road map 12G, the control
contents for the engine and automatic power transmission on the
basis of the anticipation in the height information are corrected
using the data base of the recorded past driving force state. since
the same reference numerals in FIGS. 15A and 15b as shown in the
case of the first embodiment designate corresponding elements in
the case of the first embodiment, the detailed explanations thereof
are omitted here.
The running road estimating block 13G derives the present position
of the own vehicle on the road map searched from the rewritable
electronic road map 12G on the basis of the data on the absolute
position derived from the own vehicle position specifying block
11.
Then, the running road estimating block 13G derives the estimated
position of the own vehicle located at a position several tens
meters through 100 meters ahead of the present position along the
road on which the vehicle is running and located several seconds
after the time at which the vehicle is at the present position.
The running road estimating block 13G holds therein various data
searched from the rewritable electronic road map 12G according to
the present position and estimated position. The various data
include data representing an accuracy of the past estimation of the
driving force at the estimated position. The driving force
predicting block 15G estimates the required driving force at the
estimated position on the basis of the height data between the
present position and estimated position read from the running road
estimating block 13G and transmits the result of estimation of the
required driving force integrated with the data representing the
accuracy of the past driving force estimation to the driving system
controlling block 16G. The driving system controlling block 16G
determines the settings of the engine and associated automatic
power transmission on the basis of the estimated result of the
required driving force and corrects the contents of the settings on
the basis of the data representing the past estimation accuracy of
the driving force.
The generated driving force calculating block 31 calculates the
ever-changing generated driving force on the basis of the running
resistance derived at the running resistance measuring block 14.
The evaluation block 32 holds the driving force estimated by the
driving force predicting block 15G up to a time at which the
vehicle has reached to the estimated position, prepares the data
representing the past driving force estimation accuracy from the
estimated driving force and the generated driving force at the
estimated position, and records the data in the rewritable
electronic road map 12G as the data at the estimated position. The
rewritable electronic road map 12G is previously mapped in the same
way as shown in FIG. 13B and is such that the various data recorded
therein is searchable for each position on the roads. The data
representing the past estimation accuracy of the driving force
stored in the electronic road map 12G is increased and fulfilled
whenever the vehicle runs on the roads so that the situation that
the location naturally has not appearing on the well known road map
is appropriately reflected.
Specifically, the driving force control executed in the seventh
embodiment will be described below.
Suppose that, referring back to FIG. 14, the own vehicle is running
on the position P on the road. At this time, the height at the
position x the predetermined distance remote from the position P in
the vehicular forward direction is read in anticipation from the
rewritable electronic road map 12G and the driving force predicting
block 15G estimates the ever-changing the driving forces on the
basis of the gradient variation at the interval of distance to the
position x. Then, the driving system controlling block 16G sets in
anticipation the switching characteristic of the gear range
shifting characteristic and lean or stoichiometric air/fuel mixture
ratio of the engine on the basis of the result of estimation.
In parallel to these estimation operations, the evaluation block
32, as shown in FIG. 15B, compares the driving force at the point
of road x estimated by the driving force predicting block 15G at
the preceding point of road before the point of road x and that
actually confirmed at the point of road x by the generated driving
force calculating block 31 so as to derive a deviation therebetween
(predictive error), at a step 201.
The evaluation block 32, at the next step 202, records this
deviation (predictive error) on the rewritable electronic road map
12G as the data on the own vehicle position (P=x) variable from
time to time.
In the case where the own vehicle runs on the same road many
numbers of times, this deviation is averaged so as to be recorded
with the past data updated.
In addition, the evaluation block 32 stores an average of the
deviation between the actual value and the predicted value as
described above and the standard deviation onto the rewritable
electronic road map 12G.
Next, suppose that in a case where the vehicle runs on the same
road as shown in FIG. 14 at the next time, the vehicle is now at
the position P. The running road estimating block 13G searches the
point of road x from the rewritable electronic road map 12G to
anticipate the point of road x and reads the height information
therefrom. At the same time, the running road estimating block 13G
reads the average value between the actual value and predicted
value of the driving forces and its standard deviation when the
vehicle has run at the previous time of run. If this average value
and the standard deviation are relatively large, the driving
situations are often varied so that it is estimated that it is the
driving state which is difficult for the driving force to be
predicted. In this case, even if the road in the forward direction
is flat, the driving system controlling block 16G does not adopt
the lean burn air/fuel mixture ratio control mode and the higher
geared shifting characteristic but selects the normal settings,
namely, the stoichiometric air/fuel mixture ratio control mode and
the normal characteristic of the gear range shifting characteristic
of the automatic power transmission.
In the driving force controlling apparatus of the seventh
embodiment, the possibility of repeating the same setting errors is
reduced in the locations where the vehicle driver has felt the
insufficient power due to an erroneous prediction of the driving
force at the past time and where an uneconomical running has been
executed with the setting of excessive driving margin at the past
time.
In addition, in a location where the prediction is difficult, a
deterioration of the vehicular driveability due to the difference
between the actual value and the predicted value would not be
brought out.
In addition, since the difference between the predicted value and
the actual value of the driving force is stored in the memory area
corresponding to the map, the recording medium only may be carried
into a personal computer (PC) installed in a office or plant to
analyze a tendency of the prediction accuracy or to observe the
result of predictions so that the carried record medium can serve
as a reference document to correct coefficients used for the
required driving force.
It is noted that in place of the anticipation control by means of
the driving system controlling block 16G, the driving force margin
may be calculated on the basis of the data on the past driving
force predictions and the driving system controlling block 16G may
control the adjustments of the settings in the engine and automatic
transmission on the basis of the required driving force added with
the driving force margin in place of the anticipation control by
means of the driving force controlling block 16G. Furthermore, in
place of the derivation of the actually generated driving force
from the driving system output axle using the torque sensor S1, a
variable corresponding to the generated driving force from the
outputs of the other sensors that the torque sensor S1 may be
calculated.
(Eighth Embodiment)
FIG. 16 shows a functional circuit block diagram of an eighth
preferred embodiment of the driving force controlling apparatus
according to the present invention.
FIGS. 17A and 17B show explanatory views for explaining a detection
of the vehicular driver's operation intention.
FIG. 17A shows a variation of an operation on an accelerator due to
a change in a mental state of the driver. FIG. 17B shows a
detection method of the accelerator operation pattern.
In the eighth embodiment, the driving system controlling pattern is
varied before and after the perception of a sudden change in mind
of the vehicular driver although the anticipation control described
in the seventh embodiment is based. For example, in a case where a
gentle driving attitude becomes abruptly changed to an violent
attitude, the driving force enforcement has a priority that the
suppression of the fuel consumption.
The same reference numerals as in the case of the first embodiment
designate corresponding elements shown in FIGS. 1 and 2 and the
detailed description of the same reference numerals will be omitted
here.
The running road estimating block 13H derives the estimated
position several seconds after the time at which the vehicle is at
the present position on the road map. The driving force predicting
block 15H estimates the required driving force at the estimated
position on the basis of the height data at the present position
and estimated position read from the running road estimating block
13h and transmits the result of estimation to the driving system
controlling block 16H. The driving system controlling block 16H
determines the settings of the engine and automatic power
transmission on the basis of the result of estimation of the
required driving force and corrects the setting contents by
referring to the past driving force estimation accuracy. The
generated driving force calculating block 31H calculates the
ever-changing generated driving forces. The evaluation block 32H
prepares the data representing the past driving force estimation
accuracy from the estimated driving force and generated driving
force at the estimated position, the data being recorded into the
rewritable electronic road map 12H.
A driver operation intention detecting block 33 detects the
ever-changing output state of the throttle opening angle sensor S2
and identifies the present driver's driving pattern.
The running road estimating block 13H performs a data formatting of
the outputs of the driver's operation intention detecting block 33
and holds the data formatted outputs of the driver operation
intention detecting block 33 together with various data searched
from the rewritable electronic road map 12H. The data on the
driver's driving pattern is transmitted to the driving system
controlling block 16H via the driving force predicting block 15H
together with the data representing the past driving force
estimation accuracy.
The driving system controlling block 16H corrects the control
contents of the driving system based on the anticipation of the
height information according to the driver's driving pattern and
past driving force estimation accuracy. The driving system
controlling block 16H determines whether the driver's driving
pattern has varied so as to cope with the driver's driving pattern
variation due to a change in mind or mood of the driver and due to
a sudden conscious change in the destination and corrects the
control content for the engine and automatic power transmission in
anticipation of the height information.
In the eighth embodiment, a driver's mental state is identified
according to an output state of the throttle valve opening angle
sensor S2 and on the basis of the result of identification the
settings of the driving characteristics of the engine and automatic
power transmission based on the estimated driving force are
changed.
Referring back to FIG. 14, suppose that the vehicle is running on
the position P of the road.
At this time, the height of the position x the predetermined
distance remote from the present position P is previously read from
the rewritable electronic road map 12H and the driving force
predicting block 15H estimates the ever-changing required driving
force on the basis of the gradient variation for the interval of
distance up to the position x. The driving system controlling block
1611 sets the lean burn control in the engine and the
characteristic of the continuously variable transmission (CVT) on
the basis of the estimated result of the required driving force.
However, if the operating characteristic of the driver (a manner of
depression of the accelerator pedal, change in a target vehicle
velocity, an abrupt stop of the vehicle due to a direction turn
caused by the consciousness change of the driver, and so forth) is
suddenly changed, a control target value determined according to
the height at the point of road x becomes inappropriate. For
example, under such a situation that the settings of the engine and
transmission are determined with the vehicle being cruised at the
constant speed on the freeway so that the engine is in the lean
burn air/fuel mixture ratio control, suppose that the vehicle
driver abruptly changes high driving pattern to have the vehicle
run at an abrupt acceleration. At this time, since the engine is in
the lean burn mixture ratio control mode, an undesired acceleration
occurs. Then, the driving system controlling block 16H replaces the
control target value at a stage as early as possible when the
change in the operation characteristic of the driver is detected so
as to cope with the situation of the following abrupt
acceleration.
A theory of detection of the driver's driving pattern is based on
the fact that the mental state of the driver is strongly reflected
on the driver's accelerator operation.
The driver's accelerator pedal depression angle, especially, its
standard deviation and its variance have high correlations to the
driver's driving intention.
For example, as shown in FIG. 17A, the variation history of the
driver's accelerator pedal depression related to the opening angle
of the throttle valve when the vehicle driver tries to abruptly
vary the running velocity of the vehicle since a mental stress of
the driver such that the vehicle is passed by the following vehicle
ahead is encountered.
After the passage of the following vehicle ahead of the own
vehicle, the standard deviation of the operating variable of the
accelerator pedals caused by the driver is expanded.
Therefore, the driver operation intention detecting block 33 always
evaluates the standard deviation of the accelerator pedal operating
variables by the driver through the opening angle sensor S2 and
captures quickly the variation of the opening angle fro the sensor
S2 so as to cope with the sudden conscious change of the
driver.
For example, as shown in FIG. 17B, the operating variable on the
accelerator is detected for each run through 100 milliseconds and
the standard deviation and average of the accelerator operations
are derived for the data per the past predetermined time (for
example, one minute). Then, for example, an upper limit value and a
lower limit value for the variations in the accelerator operations
are set according to the average value.+-.2.times.standard
deviation .sigma.. Thus, for the accelerator operating variable
observed to fall within the upper and lower limit values, this
driver's operation pattern belongs to the same driving pattern.
However, if the observed accelerator operating variable exceeds the
upper limit value, the driving pattern is varied.
Specifically, suppose that a sampling time is 100 milliseconds at
the present time t. The average .mu. and standard deviation .sigma.
of the accelerator opening angle data are derived from the past
accelerator opening angle data beginning at (t-0.2) seconds and
ended at (t-n.multidot.0.1) seconds. It is noted that n denotes a
constant defined empirically. As the consequence, the upper limit
value is determined as .mu.+2.sigma. and the lower limit value is
determined as .mu.-2.sigma..
When the accelerator operating variable is y at the time t and the
value of y is larger than the upper limit value of .mu.+2.sigma. or
smaller than .mu.-2.sigma., the driving pattern is drastically
varied. However, since one determination cannot find the whole
situation, in the case where the data exceeding this range of
4.sigma. is continued by several numbers of times is determined to
be the drastic change in the driving pattern.
In this situation, the driving force to be generated to conform to
estimated on the basis of the gradient on the anticipated point of
road x is halted and the driving force exerted is such a normal
setting content that the large default in the vehicular
driveability cannot be impressed to every driver.
That is to say, the driving system controlling block 16H sets the
engine air/fuel mixture ratio control mode to the stoichiometric
air/fuel mixture ratio control mode and sets the gear range
shifting characteristic to the normal characteristic. In addition,
in a case where the present control target content is largely
different from the control target content corresponding to the
normal setting content and the deterioration in the driveability,
on the contrary, is considered due to the abrupt change in the
settings, a temporal setting change is reserved and the contents of
the controls are switched when the driver operates the accelerator
so that the valve opening angle is returned to zero. In this case,
if the driver does not yet release the accelerator to fully close
the throttle valve, the driving system controlling block 16H
changes, for the time being, the control target to the normal
control target so that the control based on the anticipation of the
height information is halted for a predetermined period of
time.
Since, in the vehicular driving force controlling apparatus of the
eighth embodiment, the settings of the engine and automatic power
transmission are quickly transferred to such setting of the
characteristics of the engine and automatic power transmission as
being able to cope with the variation in the driving pattern if the
abrupt variation in the driving pattern occurs due to the mental
state of the driver, the driver does not aware of the insufficient
output power of the driving system and worsened response
characteristic for the own vehicle. In addition, since a gap
between the driveabilities involved before and after the change in
the settings occurs is relieved, the driver does not confuse such a
gap as described above. Another technique of detecting the driver's
intentional operation and reflecting the driver's intention of
operation on the driving force control includes a technique such
that a line of sight of the driver is captured to help the
specification of the forward direction of the vehicle at the branch
point. For example, with a camera disposed within a vehicular
compartment so as to continuously observe a direction of the line
of sight of the driver, the driving force controlling apparatus
determines that at a position before the intersection, a direction
that the line of sight is deflected is the forward direction of the
vehicle. This is because in front of the branch point, the number
of times the driver views the branched road direction to be
forwarded are increased. If this technique is combined with the
fourth and fifth embodiments described above, such a situation that
the estimation of the branched road to be forwarded becomes
erroneous due to the sudden change in his mind can be avoided.
Furthermore, a switch associated with a wiper device may be used to
determine whether a rain fall or snow fall occurs. Then, if the
rain fall or so forth is determined to occur according to the
switch position of the wiper device, the distance to the estimated
position x from the present position may be shortened to several
meters so that the controlled characteristics may not change
rapidly even if the estimation becomes erroneous. In this way, the
driver's feeling of the incompatibility may be relieved and a
safe-driving may be assured.
It is noted that the own vehicle position specifying block in the
above-described embodiments may not be limited to the GPS receiver
shown in FIG. 2.
It is also noted that the electronic road map is not limited to the
CD-ROM play-back unit (CD-ROM driver). For example, the own vehicle
position specifying block may utilize the positional information
and height information derived from infrastructures via
electromagnetic waves or ultra-red rays irradiated from
installations disposed on sides of roads (recently, VICS (Vehicle
Information and Communication System in Japan) may be utilized).
The electronic road map is not only constituted by a generally
available CD-ROM but also may be constituted by a magnet-optic disc
(MO), PD (Photophase variable disc), a floppy disc, a ROM card for
different regional purposes (destinations) prepared individually at
offices.
* * * * *